5 ms·

The interesting bit: If an impending collision is detected that would be expected to produce a loud crash, the vehicle’s sound system plays a short interferenc

The interesting bit: If an impending collision is detected that would be expected to produce a loud crash, the vehicle’s sound system plays a short interference signal. This causes the stapedius muscle in the ears to contract, which for a split second changes the link between the eardrum and the inner ear and so better protects it against high acoustic pressures. Most importantly, the reflex reduces the damage to hearing.

xorgar831 10y ago
Here's the sound: https://www.youtube.com/watch?v=bCOw5lisrIU&t=25s https://www.youtube.com/watch?v=bCOw5lisrIU&t=25s
- Swizec 10y ago
  I might be imagining this, but I could swear I felt my ears becoming "full". Sort of like tired of the noise and numbing down? It's hard to describe but it felt similar to being on an airplane for a long time where sound becomes kind of dull because of all the engine noise.
  - 4ad 10y ago
    You are not imagining it. (I guess it depends on the definition of "imagining", but that's philosophy.) It's definitely a real effect.
  - dogma1138 10y ago
    You aren't if you use headphones and play it at close to 80db the feeling is like when you put on the active bose noise canceling heaphones and turn them on. You feel a slight pressure on your ears which is what this intended to do.
  - bane 10y ago
    You might enjoy this site then, which has several different noise "colors", each has a different kind of effect or feeling. http://onlinetonegenerator.com/noise.html http://onlinetonegenerator.com/noise.html
  - dingaling 10y ago
    It had no discernable effect on me, in a fairly noisy domestic setting including a washing machine in the background. I was expecting it to be much more penetrating. Perhaps I've ruined my hearing after years of listening to shortwave white-noise.
  - rosstex 10y ago
    I felt that as well.
Angostura 10y ago
I wonder if it as cool hypothesis that they decided to implement as a cheap bit of marketing, or whether the protective factor is actually evidence-based.
- oblio 10y ago
  That's a bit cynical of you, isn't it? Also, would you say the same thing if it was another car company that did this?
  - Angostura 10y ago
    > Also, would you say the same thing if it was another car company that did this? Why would I have something against Mercedes?
- pja 10y ago
  Did you actually read the article, or are you just here to snark on HN? Here, let me do your research for you. First link on a search for "stapedius reflex" is https://en.wikipedia.org/wiki/Acoustic_reflex https://en.wikipedia.org/wiki/Acoustic_reflex A quick search on Google Scholar for "acoustic reflex noise" turns up this paper from 1962 which states in the abstract that the acoustic reflex is more easily triggered by wide bandwidth noise than a single sinusoidal tone. http://scitation.aip.org/content/asa/journal/jasa/34/9B/10.1121/1.1918384 http://scitation.aip.org/content/asa/journal/jasa/34/9B/10.1... I think we can safely say that this work is pretty evidence based.
  - Angostura 10y ago
    Well, I read the marketing piece, yes - but thank you for pointing me at the evidence. The level of 'snark' may have been influenced by me previously reading the Soylent story. Marketing masquerading as science is certainly a thing, though not in this case.
  - fasteo 10y ago
    A friendly reminder: "a quick search on Google Scholar" is not research. That paper you mention is just a functional description of the "accoustic reflex". I don't think the parent comment was putting the existence of the "accoustic reflex noise" in doubt; rather, and I agree with him, it's its effectiveness to protect the driver in a car crash what is in doubt. The page makes a reference to a human trial in 2011. It would be great if they included a footnote with the reference to the actual paper.
mannykannot 10y ago
I have read somewhere of a click being played through tanks' crews headphones when the main gun is fired, for this reason. This was wrt 70s-era Soviet tanks.

xorgar831 10y ago

Here's the sound: https://www.youtube.com/watch?v=bCOw5lisrIU&t=25s https://www.youtube.com/watch?v=bCOw5lisrIU&t=25s

Swizec 10y ago
I might be imagining this, but I could swear I felt my ears becoming "full". Sort of like tired of the noise and numbing down? It's hard to describe but it felt similar to being on an airplane for a long time where sound becomes kind of dull because of all the engine noise.
- 4ad 10y ago
  You are not imagining it. (I guess it depends on the definition of "imagining", but that's philosophy.) It's definitely a real effect.
- dogma1138 10y ago
  You aren't if you use headphones and play it at close to 80db the feeling is like when you put on the active bose noise canceling heaphones and turn them on. You feel a slight pressure on your ears which is what this intended to do.
- bane 10y ago
  You might enjoy this site then, which has several different noise "colors", each has a different kind of effect or feeling. http://onlinetonegenerator.com/noise.html http://onlinetonegenerator.com/noise.html
- dingaling 10y ago
  It had no discernable effect on me, in a fairly noisy domestic setting including a washing machine in the background. I was expecting it to be much more penetrating. Perhaps I've ruined my hearing after years of listening to shortwave white-noise.
- rosstex 10y ago
  I felt that as well.

Angostura 10y ago

I wonder if it as cool hypothesis that they decided to implement as a cheap bit of marketing, or whether the protective factor is actually evidence-based.

oblio 10y ago
That's a bit cynical of you, isn't it? Also, would you say the same thing if it was another car company that did this?
- Angostura 10y ago
  > Also, would you say the same thing if it was another car company that did this? Why would I have something against Mercedes?
pja 10y ago
Did you actually read the article, or are you just here to snark on HN? Here, let me do your research for you. First link on a search for "stapedius reflex" is https://en.wikipedia.org/wiki/Acoustic_reflex https://en.wikipedia.org/wiki/Acoustic_reflex A quick search on Google Scholar for "acoustic reflex noise" turns up this paper from 1962 which states in the abstract that the acoustic reflex is more easily triggered by wide bandwidth noise than a single sinusoidal tone. http://scitation.aip.org/content/asa/journal/jasa/34/9B/10.1121/1.1918384 http://scitation.aip.org/content/asa/journal/jasa/34/9B/10.1... I think we can safely say that this work is pretty evidence based.
- Angostura 10y ago
  Well, I read the marketing piece, yes - but thank you for pointing me at the evidence. The level of 'snark' may have been influenced by me previously reading the Soylent story. Marketing masquerading as science is certainly a thing, though not in this case.
- fasteo 10y ago
  A friendly reminder: "a quick search on Google Scholar" is not research. That paper you mention is just a functional description of the "accoustic reflex". I don't think the parent comment was putting the existence of the "accoustic reflex noise" in doubt; rather, and I agree with him, it's its effectiveness to protect the driver in a car crash what is in doubt. The page makes a reference to a human trial in 2011. It would be great if they included a footnote with the reference to the actual paper.

mannykannot 10y ago

I have read somewhere of a click being played through tanks' crews headphones when the main gun is fired, for this reason. This was wrt 70s-era Soviet tanks.