Measuring how much sound grates on the nerves

[coppice]

There is a lot of material, mostly dating from the 1930s, about how to make a sound level measurement follow the characteristics of the human ear. There are lots of standards and instruments which implement that knowledge, in terms of spectral weighting and non-linear characteristics. However, when trying to quieten things this is quite lacking. Much of why people want appliances to be quieter is due to the character of their sound, rather than its perceived intensity. A nice gentle whoosh from a smooth running fan is far more acceptable than a sound like nails on a blackboard of the same weighted intensity. Does anyone know of any specs or tools which attempt to measure sound in an annoyance weighted manner? Its clearly going to be imperfect, as people don't agree on which kinds of noise are the most annoying, but since some, like nails on a blackboard, are universally loathed there must be considerable common ground.

[Roehrenonkel]

Hi coppice,
 
first address would be: https://www.bksv.com/de/knowledge/applications/environmental-noise
 
Hope it helps

[Conrad Hoffman]

If you haven't seen it, I think this is a good read- https://www.acoustics.asn.au/conference_proceedings/AAS2013/papers/p39.pdf

[donlisms]

A first approximation is not terribly difficult; folks who run sound systems or mix music one way or another have always had to deal with this.

You'll notice from one of those loudness curves that there's a strong dip in required input between about 2kHz and 5kHz.  Inverted, that becomes an annoyance graph.  In practice, prominent amplitudes in the 2kHz to 3kHz region are the most annoying.  They are harsh, shrill, nails-on-chalkboard, baby-crying, and so on.  I use the word "bitey" and make a sort of grabby claw form with my fingers, and then I say "in your face."

I'm assuming a fairly full band of harmonics in this region; you can be quite annoying with a single tone, but the nature of hearing and typical sounds, the harmonics of "ordinary" waveforms at "ordinary" frequencies, tend to fill in the upper part of the spectrum quite effectively.  Not always.

In music especially, if you resolve the spectrum into a few interesting bands, you can generalize the impact those sounds have.  It's generally "too much does this", and in this case, we have shrill and harsh.  Annoying.  I'd also say "cheap", because low-quality speaker systems and such have an abundance of these frequencies, with little to balance against.  And "out front", "in your face."

At the other end for a band, "not enough does this," and in this case, the sound recedes, moves into the background, has no presence, sounds hollow, lost, easily overwhelmed by other sounds mixed in (if we're dealing with a mix).

Somewhere in the middle is "just right," enough of the... lower high end, or upper midrange, to have presence and... visibility, I guess I might say, but not so much to become annoying.

I think the perceptions in a musical mix transfer quite well to non-musical contexts.  That particular gear train, or elevator chime, or cheap speaker, or whatever.

Personally, the next most annoying factor for me, at least in music, is ANY strong resonance in a context where a nice balance is expected.  I think this becomes more psychological than physical; a resonance will introduce a noticeable constant-pitch tone that is just too strong and doesn't belong there.  It's as if someone bangs a hollow log or whatever, whenever the excitation sounds pass across that frequency.  Maybe "distracting" would be a better word than "annoying" in some if these cases.

So I suppose the tools are an FFT and some goals across the spectrum. 

[jbb]

I can’t offer any specifics, sadly.

But I can say that there are a number of specific sounds with a substantial variation from person to person. Like rap music. Or crying babies. Or the sound of someone eating.

[jpanhalt]

There are studies of the effects of frequency on annoyance and even psychotic behavior.  High frequency, say a passing motorcycle or such are annoying, but can often be ignored or diminished with sound proofing.  Low frequency -- even below perception -- can be worse.  That has been an issue with wind turbines.  Many years ago, I had an office with VLF sound/vibrations from nearby ventilation systems.  One didn't even notice the noise on first visit, but after a few hours/days/months of the continuous sound, it was impossible for me to work there.

There is scientific literature on it and governmental studies.  Here's a news report that should not be taken as science, but incidents in Taos, NM are well known.  https://bigthink.com/culture-religion/this-mysterious-sound-drives-some-to-insanity-suicide/

[TUMEMBER]

Look for studies on "tinnitus". Sensitivity to this range of irritating sounds is also related to the beginning of changes in the Central Nervous System and the hearing aid. At some point in their lives, this affects 1/3 of the 50+ population. It is then worse because we hear a sound that "is not there" and from which we cannot get away/escape from it in any way.

[jbb]

I’m curious: are there any sounds which can provoke a bout of tinnitus? (I’m the immediate sense, not in the “we weren’t very diligent with the ear protection back in the 80s” sense.)

[donlisms]

The surest way is an impulse, eg dropping something hard on a hard surface. This is broad band, high energy, and it's like flipping the tinnitus "on" switch.  To me it seems like the total energy level; a long drive in the car will do it. 

Assuming other stimulus is removed (eg food allergies, medicines, whatever!), a long sustained quietness will allow it to fade to minimum.