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I have been researching about this and it looks like the term would be auditory arousal threshold. Imagine you fall asleep while listening to music with earbuds. Out of a sudden, the device starts playing really loud music (let´s say 40 dB higher compared to what you were listening). This sound would be quite loud that it would damage your ears. My question is, is there any study showing which would be the minimum dB level of a sound that would make you wake up (and, well, remove the earbuds)? I would assume this would depend on the frequency of the signals as well. But, what about the age of the person?

the_moon
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    I don't think this is generally answerable with a single value for all people. The answer would vary from "not very loud" for light sleepers to "impossibly loud" for those who are completely deaf. – kmm Sep 19 '18 at 14:16
  • Yes, I understand what you mean. But I was expecting something like an offset that would be a general norm for most people. Let´s say: Subject A has no hearing loss and we could say they would wake with a 90 dB sound. Subject B has a hearing loss of 20 dB and therefore they would need 110 dB to wake up in the majority of cases. Let´s assume hearing loss is flat and the sound is white noise for simplicity. I have also read that the brain can adapt as well and if they are accustomed to white noise during the day, it might not wake them up. – the_moon Sep 19 '18 at 14:30
  • Can we say no more damage can be caused to the ear when the threshold is exceeded an damage has been already caused? Let´s say a person with no hearing loss, according to OSHA, would not get their ears damaged if they do not listen to 90 dBA for more than 8 hours. If this limit has already been exceeded and the subject has hearing loss, can we say instead of 90 dB, they can be exposed to 90 dB + Offset for 8 hours now? – the_moon Sep 19 '18 at 14:34
  • No general answer would make sense, as kmm points out. It's too dependent on the conditions and the individual: it will even vary for an individual from day to day. This is one reason alarms often have volume controls... Loud noise is not safe for people simply because they have hearing loss, if anything it's putting them more at risk for more profound hearing loss. – Bryan Krause Sep 19 '18 at 15:25
  • Ok, not even something similar to what I suggest in my first comment? I have been researching but could not find anything like this and wanted to give it a last try here. My background is EE and not medical... I can understand that someone that is completely deaf would not detect air pressure change as their hair cells could be nonexistent or maybe the nerves may be ruined. But, what if the brain gets a volume change (after the signal gets into the brain) of 20 dB, would this be enough for it to wake up? – the_moon Sep 19 '18 at 15:51
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    It's not just about hearing loss. Your threshold for wake up is going to depend on how tired you are, the nature of the sound, what stage of sleep you are in, other personal differences, etc etc. From an engineering perspective, you need to consider the risks of failure: you will want a different level of sound if wake-up is very necessary (i.e., fire alarm) versus if it's okay to miss some % of the time. – Bryan Krause Sep 19 '18 at 16:30
  • @Bryan Krause: Yes. I can be woken up by stealthy movements in my supposed-to-be-empty house, yet in my younger days slept through any number of raucous parties in neighboring apartments. – jamesqf Sep 19 '18 at 17:31
  • @BryanKrause, Yes, I am actually trying to look for a dB level which would guarantee that any person would wake up to (except deaf people, for sure). Imaging you have BT earbuds that play an alarm that the rate of failure must be 0%. The question would be how loud the sound needs to be and of course the type of sound. In other words, how high that threshold could reach considering all the circumstances known – the_moon Sep 19 '18 at 17:40
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    @the_moon Yeah, sorry I don't feel like that's something answerable here, it's not relevant to biology, just your engineering project. – Bryan Krause Sep 19 '18 at 17:45
  • Well, it is the biology of the human ears and the auditory system. I thought that my question would be useful and interesting here. Of course, it has value to me now but it might have value to others as well. – the_moon Sep 19 '18 at 17:50
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    Humans are not standardized components, which is what makes human factors engineering so hard. 80 percent of children between the ages of 2 and 13 did not wake up from a standard issue alarm. – Charles E. Grant Sep 19 '18 at 19:39
  • A conventional wisdom is that a sleeping mother can hear her child crying on the other end of the house, but not a cannon firing next to her ;) So it is not just sound intensity that matters. – Roger V. Nov 19 '21 at 08:31

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