Truck reversing sound - Page 1
Forum section: electronics / general

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 13, 2020, 02:54:33 pm
content: So we all know big trucks and construction equipment beeps when backing up to warn that you will mushed into paste if the truck driver doesn't see you back there.Recently I heard something new: a kind of white noise screeching when a truck was backing up near my home. It wasn't a construction site or that big of a truck either.But I did notice that the sound while lower in volume than the beep was much easier and quicker for me to identify. I wonder if they changed from a tone to a noise because it is easier to pick out as well as being quieter?Seems to me that the pure tone of the usual beeping is sometimes hard to locate in areas where there are lots of echoes. Or am I dreaming this?

author: AndyC_772
author_rank: Super Contributor
timestamp: August 13, 2020, 03:06:52 pm
content: It's well known that white noise, which contains a broad spectrum of frequencies, is much easier to locate than a pure tone. You're not dreaming!

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 13, 2020, 03:52:10 pm
content: Quote from: AndyC_772 on August 13, 2020, 03:06:52 pmYeah, I thought so too. Do you have some sort of reference or like maybe a safety organization that publishes something that states this?My googling is usually strong, but not for this. I get up a lot of blind alleys.

author: Bud
author_rank: Super Contributor
timestamp: August 13, 2020, 04:30:34 pm
content: Gosh, i wish the police and fire would use it tooand not only when backing up

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 13, 2020, 04:36:52 pm
content: Quote from: Bud on August 13, 2020, 04:30:34 pmIn Montreal we have variable volume sirens on fire trucks. They are quieter at night, but still use that single tone. I guess at this point it is so ingrained it would require serious effort to change everyone from a tone howler to a noise screecher.

author: duckduck
author_rank: Frequent Contributor
timestamp: August 13, 2020, 07:14:52 pm
content: I first heard that raspy buzzer sound a couple of years ago and I thought to myself "that truck's backup beeper is malfunctioning, lol". Little did I know that it was an advanced device based on scientific study of human perception.

author: Domagoj T
author_rank: Frequent Contributor
timestamp: August 13, 2020, 07:32:46 pm
content: Tom Scott has a video on it.While it is more than 6 years old, I still haven't heard it in person. Over here trucks still beep.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 13, 2020, 08:29:16 pm
content: Quote from: duckduck on August 13, 2020, 07:14:52 pmBut at the time did you notice that you had no problem locating the source of the sound, and maybe even quicker than a pure tone?

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 13, 2020, 10:39:41 pm
content: Wouldn't alternating between the white noise and the tone (at reduced volume) give the best of both worlds?

author: AndyC_772
author_rank: Super Contributor
timestamp: August 14, 2020, 02:21:34 pm
content: That's exactly what was done the first time I heard of this technique.IIRC it was used on a fire engine. The new siren would produce three short bursts of a conventional sounding tone in order to attract attention, followed by a burst of white noise to aid drivers in locating where the sound was coming from.The idea didn't catch on, sadly. No idea why.

author: Domagoj T
author_rank: Frequent Contributor
timestamp: August 14, 2020, 04:42:52 pm
content: Quote from: AndyC_772 on August 14, 2020, 02:21:34 pmMost likely because the legislation didn't step in, without which manufacturers have no incentive to do it, or more precisely have incentive not to do it, since they would be opening themselves to lawsuits.

author: Zbig
author_rank: Frequent Contributor
timestamp: August 14, 2020, 10:04:20 pm
content: The garbage truck(s) that's servicing my apartment building complex is making such kind of (pinkish) noise when backing up.

author: Halcyon
author_rank: Unknown
timestamp: August 15, 2020, 06:51:13 am
content: Broadband (also known as 'White Noise" reversing warning devices have been used on trucks here for many years.Quote from: Bud on August 13, 2020, 04:30:34 pmMany of our fire trucks, particularly used in inner city areas have "shakers" which emit a low frequency sound that causes surrounding vehicles to literally shake.