[stereocilia]

Not here. I hear the AC glare playing my system at levels of 65-75db.

If the glare is audible then that's one thing, but if you get fatigued listening at those levels then they are too loud when glare is present. If the glare were gone you could listen louder without fatigue, so, under those conditions 65-75 dB is too loud. Maybe I'm equivocating on the word "loud," but I think separating the concept of loudness from dB SPL is worthwhile.

[Russell Dawkins]

If that is true (and I'm not saying that it isn't), then we should feel the same effect watching a movie or TV, as our brain is busy putting a bunch of still pictures together to make motion. No?

Wayner

Funny you should bring that up, because there was a little known (and I think some would like to keep it little known) study a number of years ago where viewers' reactions were noted for video in formats differing in resolution and frame rate. In terms of emotional involvement, resolution had little effect, but frame rate had a profound effect. 60fps and higher was enough to trigger emotional responses similar to the observance of the same scene in reality, almost regardless of resolution. Higher resolution seemed to produce no such effect.

Similarly, it seems to me and some other ardent recordists, sample rate is more important than bit depth or word length in digital audio storage. Tim De Paravicini has said (and, apart from having a lot of respect for him, this fits my experience) that a 44.1k sample rate is "good" to frequencies of about 3500Hz and, by implication, 88.2k is good to 7k; 176.4k to 14k. This is the way I hear it, too. I know one leading British engineer who says he would happily record at 16 bit word lengths if the sample rate was 176.4. The extra bits are useful when recording, though, but once the recording is mixed and mastered 16/176.4 would seem to be enough for very high fidelity.

The frequently raised notion that sample rates beyond 44.1k are unnecessary because we only hear to 20k (if we're lucky) are off track; the reason for high sample rates are just as much about the way this affects the sound quality of the audible part of the spectrum, whether we can measure it or not. And whether we understand it or not. I freely admit to not understanding it.

Also, there way a Japanese (I think) study where the blood flow within the brain was recorded when the subject was listening to real acoustic music, a recording of same band limited to 20kHz and the same but with replay extended to 80kHz. The 80kHz recording had an effect very similar to real music, but the one truncated at 20kHz showed very different blood flow patterns

[stereocilia]

This is kind of funny; I think I suffer from almost everything you mention here (except maybe phonophobia).
Having experienced listening fatigue, I don't think it's really the same as misophonia.  Similar at times, perhaps, but not the same.  Misophonia usually occurs for me for specific noises (people chewing, rustling of plastic packaging) and results in emotional (often visceral) reactions that I'm not always aware of at the time.  For example, I'll be sitting on the couch, minding my own business (i.e., spacing out) and suddenly find myself getting irritable only to later realize it's because my girlfriend is rustling a bag of chips or something.

Listening fatigue, for me, is more related to hyperacusis or actual distortion.  I don't experience it too often anymore, but it's usually centered around glaring mids, like trumpets or female vocals, and usually in a too-loud bar or similar place.  It's more of a feeling of "Oh, God!  Make it stop!" rather than wanting to put my fist through somebody's face, which is what misophonia is like.^*
Or maybe I should say that hyperacusis can lead to listening fatigue?  That's probably more accurate than to say that they're related.
I used to experience listening fatigue semi-regularly when I was younger and used cheap headphones and cheap CD players.  Usually it would happen if I fell asleep while listening to music or if I had been listening for more than a couple of hours at a time.  From my experience, I'm going to agree with what others have said that it has to do with distortion and my brain interpolating what I'm hearing into something that makes sense.  I think of it as "mental dithering" and after a while my "processor" just can't handle any more and has to cool off.


^*I would like to clarify that as a general rule I don't want to put my fist through my girlfriend's face.  Though sometimes she does think it's okay to eat Airheads in bed. *rustlerustle* *glomglom* *cringe*

From what I hear, and it sounds like you have first-hand experience, misophonia can be a real drag. ugh.

I think of hyperacusis as an abnormally low pain threshold for sound. So, the sound only has to be there for a moment or two; if a sound is going to be painful it's going to be painful almost immediately. The treatment for hyperacusis and tinnitus, by the way, generally should NOT involve earplugs. Too much quiet has a good chance of making it worse.

[FullRangeMan]

I wonder if anyone on AC doesn't or hasn't experienced listener fatigue! 

I quite often have it, even with my hp HE400(its the PC sound board I suppose).

[stereocilia]

I'm thinking of two different definitions for listening fatigue.

1) unwanted loudness after some time even though the level is unchanged. This would be the exact opposite of adaptation (i.e. refractoriness). But, I can't think of a physiologic reason for that to happen, and I was the only one who suggested that's what we could mean by fatigue (because sometimes I argue with myself).   

2) feeling mentally worn out from actively paying attention, or actively ignoring. So, the fatigue goes away when you tune out even as the music plays on. It's exactly the feeling you get when you want to hear what somebody has to say, but they are just too hard to understand because of a crappy clogged-up cell phone mic in the wind.

So, yeah, now I think definition 1 that I invented is a myth. Definition 2 is real, but it's just mental fatigue.

[megabigeye]

From what I hear, and it sounds like you have first-hand experience, misophonia can be a real drag. ugh.

I think of hyperacusis as an abnormally low pain threshold for sound. So, the sound only has to be there for a moment or two; if a sound is going to be painful it's going to be painful almost immediately. The treatment for hyperacusis and tinnitus, by the way, generally should NOT involve earplugs. Too much quiet has a good chance of making it worse.

Misophonia is mostly only a drag when I'm tired or irritable or stressed.  Otherwise I can mostly actively tune it out.  Even so, I don't really think of it as a drag so much as some people's chewing just sounds extra gross to me.    I'm sure other people suffer from it more acutely than I do.  It's kind of an interesting phenomenon and I'd like to know more about it as I've just recently learned about it.  From my own experience, I wouldn't be surprised if it was actually related to some sort of emotional recall.  I can distinctly remember early incidences of each of my trigger noises.

I should admit that I'd never heard of hyperacusis until last night, but reading a little about it sounds like what I've experienced in the past (just today, actually).  If it's what I've experienced it is a low pain threshold for certain (loud) noises, but for some reason they seem to cause resonances and distortion that nobody else hears.  I'd explain it like this: imagine the pitch of, say, an ambulance siren at a high volume; normally it starts out being clear, then as it gets louder it becomes slightly uncomfortable and distorted, and then can suddenly sound like a speaker severely clipping, which can be pretty painful.
I used to have a Dayton DTA-100a and the way it would distort when playing Miles Davis was very similar sounding.

Also, I'd argue that listening fatigue is probably mostly just fatigue, as somebody else already suggested.  Will your ears get fatigued after listening to something at a high volume?  Sure.  Will your brain and ears want to give up after listening to something really intensely for hours on end?  Most likely.  Will your ears feel fatigued when you're otherwise feeling wiped?  Makes sense.
I think my point is that there are probably many factors that should be taken into consideration when trying to study listening fatigue.  Rather than trying to answer "what is the one reason for listening fatigue?" instead take a more holistic approach, taking into consideration sound reproduction, environment and room acoustics, as well as the listener and all of his or her moods and conditions.  Sounds daunting, but I'd bet it'd give a better representation of what's actually happening.

[haiderSonneteer]

Good morning all.

Thank you for all your responses so far. I have been under a rock (in front of spreadsheets) for the last couple of days so have not had my eye on this. I promise to read every bit of it and come back to make comment. It  is indeed a fascinating area.

Haider
sonneteer.co.uk

[haiderSonneteer]

Scotty,

I have walked out of concerts because the musicians and or the music sucked.  I would say I get fatigue from bad live music.  Actually, I don't get to the point of fatigue.  I just leave.  But I am going to infer that there is fatigue from live music because I would have had them if I stayed.

Yes, thank you, a reasonable point. My current thinking is non-linearity of some kind is the key. Though admittedly not all non linear reproductions will cause this. Warm distorted guitar sounds are a good example.

I find non-amplified(electronically) live irritating only when it's a bit off key or if the local acoustics are poor. Usually echoes or harsh reflections of some sort.
Haider
sonneteer.co.uk

[haiderSonneteer]

Similarly, it seems to me and some other ardent recordists, sample rate is more important than bit depth or word length in digital audio storage. Tim De Paravicini has said (and, apart from having a lot of respect for him, this fits my experience) that a 44.1k sample rate is "good" to frequencies of about 3500Hz and, by implication, 88.2k is good to 7k; 176.4k to 14k. This is the way I hear it, too. I know one leading British engineer who says he would happily record at 16 bit word lengths if the sample rate was 176.4. The extra bits are useful when recording, though, but once the recording is mixed and mastered 16/176.4 would seem to be enough for very high fidelity.

The frequently raised notion that sample rates beyond 44.1k are unnecessary because we only hear to 20k (if we're lucky) are off track; the reason for high sample rates are just as much about the way this affects the sound quality of the audible part of the spectrum, whether we can measure it or not. And whether we understand it or not. I freely admit to not understanding it.

Interesting thought. Though I am more inclined to think that this is a red herring. Though you are absolutely right that the Nyquist rate as it is called, by sampling 2 x the bandwidth (0 to 20kHz in this case) encapsulates all the data is in itself too simplistic and higher rates and of course don't forget oversampling will give better results on an ideal system, I doubt it is the obvious cause of any distortion. I have heard many a CD player out perform an SACD and DVDA player of similar high end credentials.

A simple example of my own experience: take a perfectly natural sounding system which I can listen to for hours without trouble at lower volumes shall we say then change the interconnect cable. Suddenly, it sounds so much clearer for 5 minutes, maybe even 10 or 15 minutes. Then by the time 29 minutes has been reached, my ears are hurting and I really need to switch off. This is an experience I had recently and it is purely in the analogue domain.

Yes it was probably a slightly harder sound, but not obviously so. Yes it was probably a slightly brighter sound, but again not obviously so. So what is being subtly tickled here enough to annoy and cause slight pain?

Haider
sonneteer.co.uk

[haiderSonneteer]

Hi all.
After a few years I have discovered that my ex-Naim ss amplifier
was irritating me, if you see what I mean,
I could not listen to music more than one hour,
there was something inside me that irritate me,
a sensation of fatigue and discomfort.
Now that I am tubes user, that went a way.
However, whrn I had my Audio Nirvana 8" full range driver
the big peak between 1KHz and 5KHz made music listening very tiriing.
But now, with my Omega 7F OBD with my Decware tube amplifier
that's all things of the past.
Solid state amplification is only for ambiance
and background music.

Guy 13

Well may be it is that simple. There are peaks at certain frequencies that simply don't play well with our ears. But would it suggest that they only need to be subtle ones to cause annoyance? It would also suggest that poor quality systems can sound OK over long listening periods if these frequencies are simply kept under control?

Haider
sonneteer.co.uk

[haiderSonneteer]

Dave mentioned it but I want to emphasis I believe (yep, its a "belief" because I don't have scientific evidence) controlling EMI/RF is very important to reducing not only listener fatigue but physical fatigue in general.

Well if there is enough belief out there it must be real we should be able to get scientific evidence of it. Excepting Father Christmas of course

But seriously, there is clearly something and would be interesting to know if any 'experts' have been onto it.

Haider
sonneteer.co.uk

[stereocilia]

Misophonia is mostly only a drag when I'm tired or irritable or stressed.  Otherwise I can mostly actively tune it out.  Even so, I don't really think of it as a drag so much as some people's chewing just sounds extra gross to me.    I'm sure other people suffer from it more acutely than I do.  It's kind of an interesting phenomenon and I'd like to know more about it as I've just recently learned about it.  From my own experience, I wouldn't be surprised if it was actually related to some sort of emotional recall.  I can distinctly remember early incidences of each of my trigger noises.

I should admit that I'd never heard of hyperacusis until last night, but reading a little about it sounds like what I've experienced in the past (just today, actually).  If it's what I've experienced it is a low pain threshold for certain (loud) noises, but for some reason they seem to cause resonances and distortion that nobody else hears.  I'd explain it like this: imagine the pitch of, say, an ambulance siren at a high volume; normally it starts out being clear, then as it gets louder it becomes slightly uncomfortable and distorted, and then can suddenly sound like a speaker severely clipping, which can be pretty painful.
I used to have a Dayton DTA-100a and the way it would distort when playing Miles Davis was very similar sounding.

Also, I'd argue that listening fatigue is probably mostly just fatigue, as somebody else already suggested.  Will your ears get fatigued after listening to something at a high volume?  Sure.  Will your brain and ears want to give up after listening to something really intensely for hours on end?  Most likely.  Will your ears feel fatigued when you're otherwise feeling wiped?  Makes sense.
I think my point is that there are probably many factors that should be taken into consideration when trying to study listening fatigue.  Rather than trying to answer "what is the one reason for listening fatigue?" instead take a more holistic approach, taking into consideration sound reproduction, environment and room acoustics, as well as the listener and all of his or her moods and conditions.  Sounds daunting, but I'd bet it'd give a better representation of what's actually happening.

Maybe there is a spectrum of misophonia going from mildly irritating or fatiguing to intense hatred. That would make sense. Again, I'm back to the idea that fatigue is some sort of misophonia instead of some strange kind of signal-induced hyperacusis.

Hyperacusis is thought to be caused by the outer hair cells of the cochlea failing to compress the incoming sound normally. Although, it can be more central (nerve and brain).

Ears will definitely distort at very high volume levels. There is also a muscle reflex in the middle ear that is triggered by loud noise. Normally, the stapedius and the tensor tympani muscles will contract and stiffen up your middle ear system slightly. It's very rare but possible to be born without that reflex, and for many people it's difficult to trigger at 4 KHz and above. The acoustic reflex works like a slow-acting mechanical compressor.

If I get a chance, I can ask my scientist friend if listening fatigue might literally be muscle fatigue from the middle-ear reflex being on constantly. I hadn't thought of that until just now.

I think you're right about studying listening fatigue. The more variables at work the harder it is to isolate them, and the more subjective something is the harder it is to put meaningful numbers on it.

[haiderSonneteer]

I think you have to define what distortion is. In my view, it's anything reproduced that is not as the original. So if the speed is too fast or too slow, that is distortion. If the volume you are listening to the recorded music is not the same volume as the original music was played (and then recorded), its distortion. If the spectrum of musical reproduction is not the same as the original recording event, its distortion. Then (but not finally) the grinding brutality on our ears by something gone wrong (electrically or mechanically) during reproduction is distortion.

So I ask myself, can we have distortion during a live event in which none of the instruments use pre-recorded (samples) as in a synthesizer? But what if a guitar string buzzes on a fret, is that not distortion? Or is that the character of the note. And if we have a dirty Hammond B3 organ playing into a Leslie speaker, is that not distortion?

Could I become fatigued listening to a live event with all natural type of instruments? And then, what happens if I do not like the music? Will I get fatigued really quick because of internal conflict (its music, and I like music, but not this kind.....)

Wayner

Hi thanks. I think you make some excellent observations here. THD as presented certainly does not paint the whole picture with regards to non linearity and distortion.

Haider
sonneteer.co.uk