Yes I wondered the same thing. Just to add to the question, wouldn't a button in the cabin be better - I do wonder if people hear the beeps and think you are being aggressive / telling them off for bad driving / not getting over
@@nickthorley1 They're trained to have both hands on the wheel for optimal control, so I think the horn is handiest for something regularly operated. With how complex newer cars are, how many different models, etc are used as emergency vehicles, how little time they stay on the fleet, and so on, I don't imagine there's any value in trying to teach the outfitter's technicians in every single manufacturer and small change they make for facelifts, etc just to have a separate button on there. Also, even if they did, that would be a small button not centred on the wheel (because of the airbag) and the siren could require activation while steering, so the driver would be fumbling for a small button that's never in the same place in space. On most vehicles now, the whole central section is the horn, so easily hit no matter the steering angle or how much the vehicle may be bouncing over a rough road, etc, so no issues like if you try to press a windscreen demister button or similar in the centre of the dash when going over a speed bump for example.
I wondered that as well for ages - I always thought it was a way to thank people for pulling over but I asked a few videos back and someone explained it was to change to siren. Made perfect sense when someone explained it 🤣
Spectacular! Thank you! What I'm missing is HUGE TRAIN HORN for all drivers who don't seem to hear all the sounds you're using. Such situations drive me crazy.
While I agree there are many people that need to be more aware and use mirrors more, depending on the speeds of the vehicles involved and surrounding environment sirens don't always carry well. Great for built up areas or generally slower roads but on a motorway doing 70 I usually see the emergency a fair way back in my mirror before actually hearing the siren.
Very useful. I thought you were sounding the horn separately to get people's attention. Now I understand why you sometimes hear the car horn on the audio.
Many response vehicles also have a 4th tone, usually referred to as euro twos, which is basically as it says in the tin, a european style two-tone. This tends to be more common in London due to the high tourist footfall, and the sheer number of sirens that can be heard at any one time, even when not in convoy. I can program my system to cycle through 7-8 different tones, if desired. For the sake of familiarity and driver work load, I select the usual 3 tones in the usual order. I do quite fancy a "rumbler" setup for a couple of the vehicles more often used in dense urban environments.
How do you select which tones will be in the sequence and the order. One of the police cars at my work has the classic 3 but they're in backwards order which is annoying
@@Thomashorsman That is usually done on the siren amplifier/controller. This may be at the factory, by the installer, or fleet services. I have some that are programmed by a small display panel and a couple of push buttons (or my laptop), and a couple that are set with miniature flick switches on the rear of the unit. It is not configurable by the actual user on any unit I have ever come across.
The ubiquity of sirens in London is partly why Special Escort Group use whistles. Was quite interesting being stopped by a guy on a bike in Cambridge earlier this year (9th May) who was blowing a whistle, I wonder who's being escorted through... next thing the newly minted King is being whisked past in the midst of a small convoy, the bike cop waves thanks and heads off 😅
I have to admit, I miss the old two tones (2 alternating horns) as I always struggle to work out where the emergency vehicle is with tones that are rising and falling. I believe the brain uses changing tones to calculate speed and distance (it can compute the doppler effect). Could just be my duff ears though! Good interesting video, always clear and informative.
I agree. I have always found that if I was sat in traffic, I always knew which direction an emergency vehicle was coming from if they used the two-tone sirens.
"Wailing" sirens, the ones that slowly rise and fall in pitch are almost impossible to determine the direction. There's science to that, which boils down to how our ears use the time difference between one another and how low frequency sound waves mess with that. It's the reason many newer industrial vehicles use white noise pulses instead of the old sine wave "beep" pulses when reversing. That's why EMS vehicles will switch to the "piercer" tones when they want to get the attention on people close by, it's higher frequency - though still not as good as straight up white noise.
The good old nee-naws I remember from my childhood, and the blue lights with the physial revolving reflectors. The police still use two-tones sometimes, but it is a higher pitched electronic sound rather than actual horns.
Yes, having seen the recent video (was it Tom Scott?) about directional hearing, I agree. But there is probably no easy happy medium between directional locatability and distance projection.
Your videos are quite helpful as a new American EMT learning how to do emergency driving. One interesting thing I noted is how manual sirens come into this equation, like the Q siren on American fire engines. Stays lower in the frequency range when low traffic and long roads, but the engineer usually winds it up to a higher frequency when traffic is intense or at intersections, when more directionality is needed.
Always seemed to me that, like a lot of aspects of American firefighting, the manual Q siren is a legacy or "traditional" tool. It's not better than modern solutions, but it functions and US fire depts aren't famous for being very adaptable or open to change
@@GeorgeThoughts while i do agree on some aspects, the Q is actually better at penetrating the extreme soundproofing of modern cars than electronic sirens, simply due to the frequencies produced from an actual acoustic process
They need to show this video on future blue light courses! They never went into depth on siren use on my course and I think the only thing we were taught on this subject was to change siren for each new hazard. I have to say, though I've naturally picked up the same method as you throughout my career without being taught, I think this way of driving does come naturally to emergency response drivers.
American here, I was taught to stay on the wail except for super dense traffic or intersections. Neat to see how the philosophy changes across the pond.
Slight correction, if I may, Chris!? You have a wail, *yelp* and phaser. A two-tone siren (or two-tone horns as they used to be called) is a different sound, often considered old-fashioned but still ocasionally part of the siren setup on police or fire vehicles more so than ambulance. But great video! Good job explaining the different siren purposes and the benefits of each one in different scenarios. If you do a follow-up, perhaps you might want to touch on the different siren uses when traveling in convoy and how different tones on different vehicles can help other road users be alert to expect more than one emergency service vehicle requiring to make progress? Nice work - keep it up!
I'd agree. Two tones are the nee-nah from before the 1980s. Sirens sounded very American to me when they were first introduced. If you listen to Suburbia by Pet Shop Boys they sample one of the first 1980s Met Police sirens they had on the Rover SD. They used to use bells on ambulances, as seen in early Carry On films.
Thanks Rich and yes, two-tones (or old school NeeNaws as they were known) refer to more Euro sound that we don't have here in England as much so thanks for the correction as yes, what I referred to as Two Tones are actually Yelps (or WooWoos :) ). Thanks again.
slight correction to your correction haha ( ok ok I think it depends on where you are in the world too, Chris uses the terminology for his parts) but here, phaser is marked Hyper, and two tone is marked HiLo (but we still call it 2 tone lol) I agree with Chris's "Science" which is why piercers/phasers/Hypers are useless at fast highway speeds, HiLo is my fave, some studies show it is the best for people knowing where you are in all conditions
Well explained. As an emergency driver in a city, I try and cycle through the tones so that as I come to a crossroads, I change to the phaser as I find it the most effective at attention grabbing. Our vehicles have the fourth ‘two tone’ siren too which is very useful in busy high streets, etc. It’s good at both being heard from far away, but not too harsh on peoples ears like some of the other tones. It’s less good at being heard by vehicles though so less often used. My default is the wail 👍
I wonder why this isn't more generally publicised? Knowing the difference in range between the three types can give an indication of how close an emergency vehicle might be so (for example) if you hear wailers it's more distant so you can prepare to slow/stop in a safe place instead of panicking.
(Word choice of sorens depends on location/person) The two tones used are most often called yelp or something similar. Two tones are typically just two tones with no transition. Generally in place of the phaser or used as a 4th siren in the sequence.
Besides the reasons mentioned as a normal road user there's also the fact that changing the tone, etc can grab the attention. In other words there's been a change that I need to attend to. Subliminally, that vehicles now closer.
While I had worked out that one horn press was to change the siren, for some reason I thought that you pressing it twice was a way of saying "thank you" to drivers as you passed them LOL. Thanks for the explanation and thanks for all you do.
Great video, like all the others. Thanks Chris. A slight correction from me, a sound engineer: the FREQUENCIES of wailers, helps, and phasers are all exactly the same. The only difference is how fast the oscillator sweeps between the upper and lower limit. Obviously, you're absolutely correct and explain beautifully when and why each type of siren should be used, but it's actually got me wondering WHY a slower oscillation (I.e. a wailer) appears to throw further than a faster oscillation (I.e. a phaser). I'm actually not sure, but my working theory is that, in a real world which contains reflections and reverberations, a phaser-type sound is going to be more prone to destructive interference. ...but I'm not sure. If anyone knows better, I'd love to be enlightened.
My understanding was that the higher pitch tones were better 'attention getters' but actually were poor for folks trying to determine where the sound came from (the historic 'trim-phones' in an office were terrible for deciding which phone was ringing). Meanwhile the lower pitch phasers and 'white noise' generators are a lot easier to locate, but have limited attention-getting, so ideal at junctions where you want folks to implicitly know where you are. Over-all, in terms of projection, the different tones do match what was said.
Nice one Chris. I'd worked out the tekkers with the horn but I had wondered about the choice of siren. I'd hitherto assumed you changed it up as a way for people not to mentally tune it out by refreshing the sound, but the range optimisation makes a lot of sense. Keep up the the good work mate.
That was very interesting. I didn't at all realise the sirens are principally dictated by distance. I thought it was more just a case of how frustrated you were feeling!
I knew about the frequencies for different areas but what made we wonder all the time was when and why you are using the horn. Now I know it's because you are cycling through the three sirens with it - I appreciate your explanation!
Chris don't know for sure but maybe a bit before your time, but white noise cough sirens were being looked at within all the usual two tones and wailers for better directional awareness for drivers. This never seems to have been initiated by those in power at the end of the day so I dont know of any services that had these on vehicles, I think it was tech from the USA R & D suggested this was the best for directional purposes at the end of the day. Interest from me as I started out in first aid 3 years then 10 in SAR and now 15 in 4x4 response.
Thanks for this video Chris. It's good to see you explain the driving tools that get you where you need to be. One thing I've learnt is that when you cycle through the sirens, the car's normal horn sounds briefly. Until now, I always thought you were giving a little beep to other drivers as well as using the sirens. Now I know.
In the states that could be labeled as a wail, yelp, and a third siren. Different siren manufacturers have different names for the third and some have different sounds depending upon the company. Some have different names and sounds altogether. Also i"ve noticed sometimes at high speeds you tend to outrun your siren.
A quick point about the horn button: I can foresee a situation where the (ordinary) horn beeping a couple of times as you change sirens could be interpreted as you encouraging someone to move, which might work against you (you know how thick some people can be). I'm surprised that, with the blues on, the horn isn't deactivated. It's not as if you need it.
@@gblarggif the vehicle is using a full control system, it's literally 2 extra wires ran out with the siren and a NC relay commanded open when blue light mode is activated.
Awesome as always Chris great explanation, i onew about the three types as i used to repair police vehicles but didnt know the true reason behind them, actually quite naively thought it was vased on the serverity of the incident, so thank you for this...every day is a school day 👍
My question is, Chris: would you prefer your ‘siren cycler’ to be a bit more convenient? You seem to leave the box in auto (ie not using flappy paddles for shifts), so imagine you rewired the sirens to change between the different kinds as you flick the paddles. No need to hit through the horn every time you want to change back to a previous tone: just nudge a paddle with your fingers. Hands stay in the wheel.
Had an EMS come up behind me on the motorway the other day and sure enough I could hear nothing even though I had no music playing or anything, until it was almost alongside. It's quite interesting to me how little you hear it ahead.
Hi Chis, Big fan of your videos and I am always happy when I see the new video notification pop up. After waiting for 3 years to get a course, I finally have my standard blue light course coming up over the next month or so. My question is though, do you know how, if at all, blue light driving/training differs from emergency service for example, ambulance to police? Also, do you receive different training for RRV / CCT / OM vehicles which are a bit more sporty than your average Fiat Ducato DCA? I know police has for example advanced courses for anything nicer to drive than a Peoguet, is this the same for Ambo? Thank you
Chris this is excellent content, i had a heart attack on sunday my misses was in the back ofnthe ambulance with me (obviously I was knocked) but i shows her this and said the same thing that the ambulance driver used. I would love to get in contact, currently at the new cross heart department (apparently, they the next thing as slice bread). Here's hoping!!
Nice explaining about the tones, the only thing what is weird to me as a Dutch is that sometimes you switch the tones off. To me that's a sign of not a hurries anymore? In the Netherlands if you have a P1 call you keep the sirens on until you get there.
Interesting demonstration in that the headphone-wearing pedestrian at @02:30 is oblivious to you until you switch to the phasers, then he looks at you right away.
I thought as well that Wailers are hard for people to work out the direction are coming from, the frequency of the phasers makes it easy for people to work out the direction you're coming from
Great video Chris that I’m going to share with my students. I already knew about the different tones for different circumstances but it’s useful to know the name of the Piercer.
Hi Chris, thanks for the upload. It's nice and concise. I just have a question as to whether emergency response drivers have noticed a degradation in siren effectiveness over the years as more and more road users are in vehicles with climate control, so drive with their windows up, coupled with the increased noise insulation in modern cars? Is there more reliance from the emergency services correspondingly in the "Blues" over the "Twos" as the sound landscape has changed? Just curious. Thanks for the insights, stay safe out there.
Nice explanation. In germany we only have two typed "city" (like your two tones) and "countryside" (like your long wave) + on bigger ones pneumatic horns. The uk pearcers I feel are allmost not noticible for me. When visiting the UK a view weeks ago, I felt like... it's hard to hear & locate where they are comming from. Also UK's feel kine 50% the vollume then german ones. I had police behind be on the M20 and only noticed them, when they were like 150m behind me. I felt like they were a little slow for "on the run", but this might be my preception of normally having 160-220km/h (100-137mh/h) chill crouse speed. (in germany)
Ooo! Thanks. I've been wanting to see something like this from someone or somewhere for a while but haven't got around to researching it. Haven't watched it yet, fingers crossed.
I don't think its as complicated at this. For a start the 2 tones are not 2 tones as indicates in this video. 2 tones are proper hi lo like those sounds from the old air operated sirens from the 70s and 80s. The 2 tones referred to in this video is the Yelp. Which is faster than the whale. The idea originally behind this thinking was the vehicle is travelling faster that it really is as to get your attention and the urgency of the emergency the vehicle is attending too. 2 tones are still used today but few now are air operated and tend to be electronic 2 tones. Format for sirens these days tend to be Yelp/Whale/2 tone/phaser. Its a shame we've lost the ability to manually flick the siren from one to another where as now you have to cycle through them to get back to the first again. The old sets like MetSound and Code 3 had a rotating knob you could switch to whatever siren you wanted and could flick from 2tone to yelp, back to 2tone back to yelp without passing through Whale and phaser. If single crewed it did mean taking your hand of the wheel but if double crewed the front seat passenger could assist. The old siren sets were far better and different to today's which invariably sound all similar. In the 80/90s you could tell long before you saw the vehicle what service it was. At the end of the day. It just means, take your time. Be aware of your surroundings try and give the emergency service as much room as possible and let them make there way round you. Just give clear instructions what you are doing by using your indicators so the emergency service can get to there destination safely and you to yours safely. And. Always check for other emergency vehicles before pulling back out and continuing your manoeuvre.
Ha! You have answered my long running question about normal car beeps. It indicates tone change or end of tone change cycle and has nothing to do with "thank you" or "nice move" (I know sounds silly now). Just a query; The bells of way old UK emergency response cars I read they were better because they were more directional. People understood better where the car was in relation to them. Any truth in that? Mind you those cars were a lot slower and the road conditions less complex. Thanks for the content. My road observation is better after watching how you drive.
@@Nick_G7IZR I think at least some of them are thanks. I do wonder why the horn isn't used more when people aren't paying attention but I am guessing the training says not to do that.
How do you press the horn in your vehicles then? Is it just the big "button" in the middle of the steering wheel like in other cars, or is there some other switch or lever closer to your hands so you can keep both hands on the wheel? Do you just stretch your thumb to the middle of the wheel? P.S. Great and informative video and highly relevant to your other content
Very informative Chris. How about doing an 'educational' video on how road users should react to emergency vehicles? It would be useful to have a few tips on how to get out of the way in a safe and controlled manner.
For situations where you want to turn off the sirens to prevent people breaking the law (e.g. at a set of traffic lights), or where it wouldn't be safe to overtake someone (double whites), I've always wondered whether the double-tap of the horn may actually encourage people to stop / go through the lines more, as they think they're being beeped at. 🤔
I always wondered why you honked your horn so often now i know ! Do the fire and police have the same 3 or do different services have different ones ? Great Vids BTW
I know the "piercers" as "phaser" - not sure how accurate this is, suspect there is variation between stations/areas/countries! I'm in the UK up north.
Nice explanation Chris thanks. My question is what's the difference between the marked and unmarked cars you drive (apart from the light bar and graphics obviously) nand hello from New Zealand
Hi Chris I love following your channel and have always enjoyed the videos you post so please keep them coming. Could I ask a quick question? Is there a Home Office standard for Sirens that Emergency Vehicles have to use or is each service/authority free to choose their own?
From a country in which there is only one siren I found this really interesting. They tend to use it more in your context of two tones and piercers. At times they use them constantly when outside of residential areas. If you just had one siren , when would you use it most ? 😊
Thanks Chris! Was looking for something like this. I work in an emergency unit as well. I haven’t been able to find any evidence-based articles, i am looking to educate my colleagues on the use of different siren tones. Do you have any suggestions?
Are you allowed to use the horn to try and get peoples attention when they just seem to have not noticed you? Likewise can you flash your lights, for example when stuck behind a transit in a recent video you hung back so they could have a chance to notice you in their mirrors, I don't recall you saying you flashed them at all with your headlights. I thought this might work if they say had their stereo blasting out or headphones on.
Chris quick question if you’re on an open stretch of road and cars see you coming what would be preferred they pull over and stop or continue at a slower pace? I tend to pull over and stop
Love your community interaction while you're doing the heroic job that you're doing. Thanks for YOUR time, Chris!
Really interesting. I was wondering what all the horn beeps were about. Now I know it’s just cycling between siren noises.
Yes I wondered the same thing. Just to add to the question, wouldn't a button in the cabin be better - I do wonder if people hear the beeps and think you are being aggressive / telling them off for bad driving / not getting over
@@nickthorley1 They're trained to have both hands on the wheel for optimal control, so I think the horn is handiest for something regularly operated.
With how complex newer cars are, how many different models, etc are used as emergency vehicles, how little time they stay on the fleet, and so on, I don't imagine there's any value in trying to teach the outfitter's technicians in every single manufacturer and small change they make for facelifts, etc just to have a separate button on there. Also, even if they did, that would be a small button not centred on the wheel (because of the airbag) and the siren could require activation while steering, so the driver would be fumbling for a small button that's never in the same place in space. On most vehicles now, the whole central section is the horn, so easily hit no matter the steering angle or how much the vehicle may be bouncing over a rough road, etc, so no issues like if you try to press a windscreen demister button or similar in the centre of the dash when going over a speed bump for example.
Now I get it why I hear horn all the time during your videos. It’s a “change siren” horn. Cheers!
I wondered that as well for ages - I always thought it was a way to thank people for pulling over but I asked a few videos back and someone explained it was to change to siren. Made perfect sense when someone explained it 🤣
@@C4sp3r123 He does double beep sometimes as a thankyou when passing the other driver
@@noahs6488 👍
Spectacular! Thank you! What I'm missing is HUGE TRAIN HORN for all drivers who don't seem to hear all the sounds you're using. Such situations drive me crazy.
They do have air horns on trucks, and with 44 tonnes on board you better get out of their way! 🙂
we need phasers that fire when phaser siren is activated.
@@graememckay9972 First, do no harm. 🙂
While I agree there are many people that need to be more aware and use mirrors more, depending on the speeds of the vehicles involved and surrounding environment sirens don't always carry well. Great for built up areas or generally slower roads but on a motorway doing 70 I usually see the emergency a fair way back in my mirror before actually hearing the siren.
Police vehicles normally have a Bull Horn, don't know about ambulances.
Very useful. I thought you were sounding the horn separately to get people's attention. Now I understand why you sometimes hear the car horn on the audio.
That point had always puzzled me too ! Nice to have it answered.
Many response vehicles also have a 4th tone, usually referred to as euro twos, which is basically as it says in the tin, a european style two-tone. This tends to be more common in London due to the high tourist footfall, and the sheer number of sirens that can be heard at any one time, even when not in convoy. I can program my system to cycle through 7-8 different tones, if desired. For the sake of familiarity and driver work load, I select the usual 3 tones in the usual order.
I do quite fancy a "rumbler" setup for a couple of the vehicles more often used in dense urban environments.
How do you select which tones will be in the sequence and the order. One of the police cars at my work has the classic 3 but they're in backwards order which is annoying
@@Thomashorsman That is usually done on the siren amplifier/controller. This may be at the factory, by the installer, or fleet services.
I have some that are programmed by a small display panel and a couple of push buttons (or my laptop), and a couple that are set with miniature flick switches on the rear of the unit.
It is not configurable by the actual user on any unit I have ever come across.
The ubiquity of sirens in London is partly why Special Escort Group use whistles. Was quite interesting being stopped by a guy on a bike in Cambridge earlier this year (9th May) who was blowing a whistle, I wonder who's being escorted through... next thing the newly minted King is being whisked past in the midst of a small convoy, the bike cop waves thanks and heads off 😅
I really like the rumbler they use in NYC
I have to admit, I miss the old two tones (2 alternating horns) as I always struggle to work out where the emergency vehicle is with tones that are rising and falling. I believe the brain uses changing tones to calculate speed and distance (it can compute the doppler effect). Could just be my duff ears though! Good interesting video, always clear and informative.
I'm inclined to agree with that, now that I think about it.
I agree. I have always found that if I was sat in traffic, I always knew which direction an emergency vehicle was coming from if they used the two-tone sirens.
"Wailing" sirens, the ones that slowly rise and fall in pitch are almost impossible to determine the direction. There's science to that, which boils down to how our ears use the time difference between one another and how low frequency sound waves mess with that. It's the reason many newer industrial vehicles use white noise pulses instead of the old sine wave "beep" pulses when reversing.
That's why EMS vehicles will switch to the "piercer" tones when they want to get the attention on people close by, it's higher frequency - though still not as good as straight up white noise.
The good old nee-naws I remember from my childhood, and the blue lights with the physial revolving reflectors. The police still use two-tones sometimes, but it is a higher pitched electronic sound rather than actual horns.
Yes, having seen the recent video (was it Tom Scott?) about directional hearing, I agree. But there is probably no easy happy medium between directional locatability and distance projection.
Very informative again Chris, thanks for explaining the situations that you use them in and how the interact with the environment/traffic.
Your videos are quite helpful as a new American EMT learning how to do emergency driving. One interesting thing I noted is how manual sirens come into this equation, like the Q siren on American fire engines. Stays lower in the frequency range when low traffic and long roads, but the engineer usually winds it up to a higher frequency when traffic is intense or at intersections, when more directionality is needed.
Always seemed to me that, like a lot of aspects of American firefighting, the manual Q siren is a legacy or "traditional" tool. It's not better than modern solutions, but it functions and US fire depts aren't famous for being very adaptable or open to change
@@GeorgeThoughts while i do agree on some aspects, the Q is actually better at penetrating the extreme soundproofing of modern cars than electronic sirens, simply due to the frequencies produced from an actual acoustic process
They need to show this video on future blue light courses! They never went into depth on siren use on my course and I think the only thing we were taught on this subject was to change siren for each new hazard. I have to say, though I've naturally picked up the same method as you throughout my career without being taught, I think this way of driving does come naturally to emergency response drivers.
American here, I was taught to stay on the wail except for super dense traffic or intersections. Neat to see how the philosophy changes across the pond.
Slight correction, if I may, Chris!? You have a wail, *yelp* and phaser. A two-tone siren (or two-tone horns as they used to be called) is a different sound, often considered old-fashioned but still ocasionally part of the siren setup on police or fire vehicles more so than ambulance. But great video! Good job explaining the different siren purposes and the benefits of each one in different scenarios. If you do a follow-up, perhaps you might want to touch on the different siren uses when traveling in convoy and how different tones on different vehicles can help other road users be alert to expect more than one emergency service vehicle requiring to make progress? Nice work - keep it up!
I'd agree. Two tones are the nee-nah from before the 1980s. Sirens sounded very American to me when they were first introduced. If you listen to Suburbia by Pet Shop Boys they sample one of the first 1980s Met Police sirens they had on the Rover SD. They used to use bells on ambulances, as seen in early Carry On films.
Thanks Rich and yes, two-tones (or old school NeeNaws as they were known) refer to more Euro sound that we don't have here in England as much so thanks for the correction as yes, what I referred to as Two Tones are actually Yelps (or WooWoos :) ).
Thanks again.
Two tones/hi-lo are awesome, shame more cars don’t have them.
slight correction to your correction haha ( ok ok I think it depends on where you are in the world too, Chris uses the terminology for his parts) but here, phaser is marked Hyper, and two tone is marked HiLo (but we still call it 2 tone lol) I agree with Chris's "Science" which is why piercers/phasers/Hypers are useless at fast highway speeds, HiLo is my fave, some studies show it is the best for people knowing where you are in all conditions
Well explained. As an emergency driver in a city, I try and cycle through the tones so that as I come to a crossroads, I change to the phaser as I find it the most effective at attention grabbing.
Our vehicles have the fourth ‘two tone’ siren too which is very useful in busy high streets, etc. It’s good at both being heard from far away, but not too harsh on peoples ears like some of the other tones. It’s less good at being heard by vehicles though so less often used.
My default is the wail 👍
I have just watched an episode of "Emergency Helicopter Medics" in which you were there with EAAA! It was great to see you in action!
Was literally googling this a week ago and couldn’t find any videos on it. Thank you!
I wonder why this isn't more generally publicised? Knowing the difference in range between the three types can give an indication of how close an emergency vehicle might be so (for example) if you hear wailers it's more distant so you can prepare to slow/stop in a safe place instead of panicking.
(Word choice of sorens depends on location/person)
The two tones used are most often called yelp or something similar. Two tones are typically just two tones with no transition. Generally in place of the phaser or used as a 4th siren in the sequence.
Brilliant explanation. That explains the occasional 'beep' of the horn.
Great breakdown, hadn't even considered the science behind the direction of sound and how they're utilised.
Besides the reasons mentioned as a normal road user there's also the fact that changing the tone, etc can grab the attention. In other words there's been a change that I need to attend to. Subliminally, that vehicles now closer.
While I had worked out that one horn press was to change the siren, for some reason I thought that you pressing it twice was a way of saying "thank you" to drivers as you passed them LOL. Thanks for the explanation and thanks for all you do.
Thank you for the insight. It’s interesting and hopefully it helps people understand what’s happening when they hear the sirens on the road.
Great video, like all the others. Thanks Chris. A slight correction from me, a sound engineer: the FREQUENCIES of wailers, helps, and phasers are all exactly the same. The only difference is how fast the oscillator sweeps between the upper and lower limit.
Obviously, you're absolutely correct and explain beautifully when and why each type of siren should be used, but it's actually got me wondering WHY a slower oscillation (I.e. a wailer) appears to throw further than a faster oscillation (I.e. a phaser). I'm actually not sure, but my working theory is that, in a real world which contains reflections and reverberations, a phaser-type sound is going to be more prone to destructive interference. ...but I'm not sure. If anyone knows better, I'd love to be enlightened.
Bless your soul Chris, thanks to all the emergency services for doing what you do!
This is one of the best channels on youtube, loved this! ....Please keep on doing your longer driving videos, I could watch them all day.
My understanding was that the higher pitch tones were better 'attention getters' but actually were poor for folks trying to determine where the sound came from (the historic 'trim-phones' in an office were terrible for deciding which phone was ringing).
Meanwhile the lower pitch phasers and 'white noise' generators are a lot easier to locate, but have limited attention-getting, so ideal at junctions where you want folks to implicitly know where you are.
Over-all, in terms of projection, the different tones do match what was said.
Thank you very much for the insight, I had no idea there was so much to it. As an apsiring ambulance officer I really appreciate your videos.
Nice one Chris. I'd worked out the tekkers with the horn but I had wondered about the choice of siren. I'd hitherto assumed you changed it up as a way for people not to mentally tune it out by refreshing the sound, but the range optimisation makes a lot of sense. Keep up the the good work mate.
That was very interesting. I didn't at all realise the sirens are principally dictated by distance. I thought it was more just a case of how frustrated you were feeling!
I knew about the frequencies for different areas but what made we wonder all the time was when and why you are using the horn. Now I know it's because you are cycling through the three sirens with it - I appreciate your explanation!
Chris don't know for sure but maybe a bit before your time, but white noise cough sirens were being looked at within all the usual two tones and wailers for better directional awareness for drivers.
This never seems to have been initiated by those in power at the end of the day so I dont know of any services that had these on vehicles, I think it was tech from the USA R & D suggested this was the best for directional purposes at the end of the day.
Interest from me as I started out in first aid 3 years then 10 in SAR and now 15 in 4x4 response.
And this also goes to explain the occasional sound of the horn we hear as you progress!
Very helpful and answered a lot of questions I had and never knew where to get the answers! 🤔
Awesome video. Thanks for sharing but more importantly, Thank you for doing the excellent job you do. Life saver !
Thanks for this video Chris. It's good to see you explain the driving tools that get you where you need to be. One thing I've learnt is that when you cycle through the sirens, the car's normal horn sounds briefly. Until now, I always thought you were giving a little beep to other drivers as well as using the sirens. Now I know.
In the states that could be labeled as a wail, yelp, and a third siren. Different siren manufacturers have different names for the third and some have different sounds depending upon the company. Some have different names and sounds altogether. Also i"ve noticed sometimes at high speeds you tend to outrun your siren.
Thank you - I always wondered why you were sounding your horn all the time, thought you were giving people a friendly honk!! 😂
A quick point about the horn button: I can foresee a situation where the (ordinary) horn beeping a couple of times as you change sirens could be interpreted as you encouraging someone to move, which might work against you (you know how thick some people can be). I'm surprised that, with the blues on, the horn isn't deactivated. It's not as if you need it.
I'd assume partly safety. It's more complex to disable the horn selectively rather than leave it wired standard from the factory.
@@gblarggif the vehicle is using a full control system, it's literally 2 extra wires ran out with the siren and a NC relay commanded open when blue light mode is activated.
@@_Steven_S It would all be done with software changes now I would imagine.
This is a great video for those not in the know that said 1:08 are yelp not two tones (or HiLo as they are often known).
Awesome as always Chris great explanation, i onew about the three types as i used to repair police vehicles but didnt know the true reason behind them, actually quite naively thought it was vased on the serverity of the incident, so thank you for this...every day is a school day 👍
My question is, Chris: would you prefer your ‘siren cycler’ to be a bit more convenient? You seem to leave the box in auto (ie not using flappy paddles for shifts), so imagine you rewired the sirens to change between the different kinds as you flick the paddles. No need to hit through the horn every time you want to change back to a previous tone: just nudge a paddle with your fingers. Hands stay in the wheel.
Very clear and useful explanations - Thanks for the upload!
Thank you, Chris. Very clear and useful explanation.
Thanks Chris really interesting. Often wondered about the horn beeps in your videos.
Best wishes and safe journies 👍
Something I'd never have thought to find out the answer for
that explains horn beeps now :-)
Had an EMS come up behind me on the motorway the other day and sure enough I could hear nothing even though I had no music playing or anything, until it was almost alongside. It's quite interesting to me how little you hear it ahead.
Awesome educational video. Especially for those across the pond :)
Hi Chis,
Big fan of your videos and I am always happy when I see the new video notification pop up. After waiting for 3 years to get a course, I finally have my standard blue light course coming up over the next month or so.
My question is though, do you know how, if at all, blue light driving/training differs from emergency service for example, ambulance to police?
Also, do you receive different training for RRV / CCT / OM vehicles which are a bit more sporty than your average Fiat Ducato DCA? I know police has for example advanced courses for anything nicer to drive than a Peoguet, is this the same for Ambo?
Thank you
Chris this is excellent content, i had a heart attack on sunday my misses was in the back ofnthe ambulance with me (obviously I was knocked) but i shows her this and said the same thing that the ambulance driver used. I would love to get in contact, currently at the new cross heart department (apparently, they the next thing as slice bread). Here's hoping!!
Absolutely amazing information and covered basically everything I've ever wondered about regarding sirens! Thanks, Chris!
Nice explaining about the tones, the only thing what is weird to me as a Dutch is that sometimes you switch the tones off. To me that's a sign of not a hurries anymore? In the Netherlands if you have a P1 call you keep the sirens on until you get there.
Wonderful video, a great clear explanation! Would love to see more informational content like this, thanks Chris!
Interesting demonstration in that the headphone-wearing pedestrian at @02:30 is oblivious to you until you switch to the phasers, then he looks at you right away.
I thought as well that Wailers are hard for people to work out the direction are coming from, the frequency of the phasers makes it easy for people to work out the direction you're coming from
Great video Chris that I’m going to share with my students. I already knew about the different tones for different circumstances but it’s useful to know the name of the Piercer.
Hi Chris, thanks for the upload. It's nice and concise. I just have a question as to whether emergency response drivers have noticed a degradation in siren effectiveness over the years as more and more road users are in vehicles with climate control, so drive with their windows up, coupled with the increased noise insulation in modern cars? Is there more reliance from the emergency services correspondingly in the "Blues" over the "Twos" as the sound landscape has changed? Just curious.
Thanks for the insights, stay safe out there.
Thank you this explains so much that I never knew.
Nice explanation.
In germany we only have two typed "city" (like your two tones) and "countryside" (like your long wave) + on bigger ones pneumatic horns. The uk pearcers I feel are allmost not noticible for me.
When visiting the UK a view weeks ago, I felt like... it's hard to hear & locate where they are comming from. Also UK's feel kine 50% the vollume then german ones. I had police behind be on the M20 and only noticed them, when they were like 150m behind me. I felt like they were a little slow for "on the run", but this might be my preception of normally having 160-220km/h (100-137mh/h) chill crouse speed. (in germany)
Ooo! Thanks. I've been wanting to see something like this from someone or somewhere for a while but haven't got around to researching it. Haven't watched it yet, fingers crossed.
I don't think its as complicated at this. For a start the 2 tones are not 2 tones as indicates in this video. 2 tones are proper hi lo like those sounds from the old air operated sirens from the 70s and 80s. The 2 tones referred to in this video is the Yelp. Which is faster than the whale. The idea originally behind this thinking was the vehicle is travelling faster that it really is as to get your attention and the urgency of the emergency the vehicle is attending too.
2 tones are still used today but few now are air operated and tend to be electronic 2 tones.
Format for sirens these days tend to be Yelp/Whale/2 tone/phaser.
Its a shame we've lost the ability to manually flick the siren from one to another where as now you have to cycle through them to get back to the first again.
The old sets like MetSound and Code 3 had a rotating knob you could switch to whatever siren you wanted and could flick from 2tone to yelp, back to 2tone back to yelp without passing through Whale and phaser. If single crewed it did mean taking your hand of the wheel but if double crewed the front seat passenger could assist.
The old siren sets were far better and different to today's which invariably sound all similar.
In the 80/90s you could tell long before you saw the vehicle what service it was.
At the end of the day. It just means, take your time. Be aware of your surroundings try and give the emergency service as much room as possible and let them make there way round you. Just give clear instructions what you are doing by using your indicators so the emergency service can get to there destination safely and you to yours safely. And. Always check for other emergency vehicles before pulling back out and continuing your manoeuvre.
Ha! You have answered my long running question about normal car beeps. It indicates tone change or end of tone change cycle and has nothing to do with "thank you" or "nice move" (I know sounds silly now). Just a query; The bells of way old UK emergency response cars I read they were better because they were more directional. People understood better where the car was in relation to them. Any truth in that? Mind you those cars were a lot slower and the road conditions less complex. Thanks for the content. My road observation is better after watching how you drive.
Great video Chris. I've always wondered about specific siren use. Thanks for explaining it so well.
Loved it mate! Can you now show us your buttons and screens in the car?
Yet another fantastic video and thank you for your critical, life-saving work!
Did not know about distance. I thought it might be priority with the phasers/piercers being an immediate danger alert. Good to know.
And there's me thinking you were also beeping people! 😆
I used to think that, or that he was acknowledging people for pulling over
@@C4sp3r123 Exactly. I thought they were a "thanks" beep or a "watch out" beep. At least I know now :)
@@Nick_G7IZR I think at least some of them are thanks. I do wonder why the horn isn't used more when people aren't paying attention but I am guessing the training says not to do that.
How do you press the horn in your vehicles then? Is it just the big "button" in the middle of the steering wheel like in other cars, or is there some other switch or lever closer to your hands so you can keep both hands on the wheel? Do you just stretch your thumb to the middle of the wheel? P.S. Great and informative video and highly relevant to your other content
I drive a fire truck, all tones of sirens are for suggesting people yield, air horns are for making them yield :)
Very informative Chris. How about doing an 'educational' video on how road users should react to emergency vehicles? It would be useful to have a few tips on how to get out of the way in a safe and controlled manner.
I say they should provide a couple of nostalgia sounds to the sirens, the pneumatic two tone and the bell, today both very uncommon sounds.
I understand that sometimes simply changing siren is a good way of getting attention
Definitely get this over to TikTok if you can. More content please😂👏👏👍
Fantastic video Chris, see you for the VRS out to demonstrate.
An excellent little lecture, thank you Chris, your films are very informative and entertaining.😎
Love this, thanks Chris. Does your vehicle have a bullhorn too? For those dire or dangerous moments I imagine
For situations where you want to turn off the sirens to prevent people breaking the law (e.g. at a set of traffic lights), or where it wouldn't be safe to overtake someone (double whites), I've always wondered whether the double-tap of the horn may actually encourage people to stop / go through the lines more, as they think they're being beeped at. 🤔
What don’t understand is why the high pitch sounds are being used. Low tones travel much farther. Even the British low tones seem quite high pitched
This is exactly what I asked for thank you! Do you ever use them (change tone) to say thank you or is it just coincidence in the videos?
Flipping love this!!
I always wondered why you honked your horn so often now i know ! Do the fire and police have the same 3 or do different services have different ones ? Great Vids BTW
Rumblers also becoming more common over in the US. Do you think those will take off here and do you think they would make a big difference?
They're common here in Australia too.
Please can you realise the full video of the bmw that got in ur way, love the videos
I know the "piercers" as "phaser" - not sure how accurate this is, suspect there is variation between stations/areas/countries! I'm in the UK up north.
Cheers Chris... much appreciated had no idea you had all 3 sirens.... At least I'll know if you're coming 😂🤣 but seriously hope not!
Nice explanation Chris thanks. My question is what's the difference between the marked and unmarked cars you drive (apart from the light bar and graphics obviously) nand hello from New Zealand
Really well explained.
Hi Chris I love following your channel and have always enjoyed the videos you post so please keep them coming. Could I ask a quick question? Is there a Home Office standard for Sirens that Emergency Vehicles have to use or is each service/authority free to choose their own?
And there was me thinking the tooting was to say a special *thanks" for executing a good manoeuvre, ah well
Excellent video,thanks
Emergency sirens I believe function the same here in Australia. When do you get to take your new vehicle out on the road?
From a country in which there is only one siren I found this really interesting. They tend to use it more in your context of two tones and piercers. At times they use them constantly when outside of residential areas.
If you just had one siren , when would you use it most ? 😊
Good stuff chris!
Can you give us a tour of your new car, like you did with the old one?
Interesting that the sirens are connected to the horn, id assume they would be extra buttons on the starting wheel
Thanks Chris!
Was looking for something like this. I work in an emergency unit as well. I haven’t been able to find any evidence-based articles, i am looking to educate my colleagues on the use of different siren tones. Do you have any suggestions?
Are you allowed to use the horn to try and get peoples attention when they just seem to have not noticed you? Likewise can you flash your lights, for example when stuck behind a transit in a recent video you hung back so they could have a chance to notice you in their mirrors, I don't recall you saying you flashed them at all with your headlights. I thought this might work if they say had their stereo blasting out or headphones on.
Thanks for the subtitles, very imformative video ❤
Chris quick question if you’re on an open stretch of road and cars see you coming what would be preferred they pull over and stop or continue at a slower pace? I tend to pull over and stop
Another great video Chris!
So how many years ago did they move from a push button to activate the siren to the vehicle wheel horn, to activate.