Hearing loss and tuning problems

Subject: RE: Hearing loss and tuning problems
From: Robert B. Waltz
Date: 06 Apr 26 - 02:44 PM

MaJoC the Filk wrote:

Ach, I've long since given up tuning totally by ear. I was given a guitar tuner as a retirement present, which gets it close enough for folk music that I can take it from there.

There is an important footnote to this: The electronic tuner can almost certainly tune to a tempered scale better than a human can. But it can only tune to a tempered scale. (Most of them.) If you are then tuning beyond that, you are probably tuning to a natural scale in some specific key. Great, if you're playing solo and playing in that key. :-) And if you retune when you change keys.

But if you don't retune when you change keys, or if you are playing with someone whose instrument has been tuned to a tempered scale, the result is worse than if play a tempered instrument. Whatever you do with a fixed-fret instrument, you have to compromise.

Which is why some old lute family instruments had movable frets.

Subject: RE: Hearing loss and tuning problems
From: MaJoC the Filk
Date: 06 Apr 26 - 01:40 PM

One effect I noticed a few years ago now is at the other end: when a bass guitar or double-bass plays alone, then is joined by other instruments, I perceive that the bass is maybe a semitone sharp, notably if the bass sounds muffled (fewer higher harmonics). Mebbe the fact that our newer TV (cheap, no sound bar) doesn't reproduce any perceptible bass frequencies has meant that my ears are out of practice at the low end. Or mebbe it's one particular Radio 4 theme tune.

Ach, I've long since given up tuning totally by ear. I was given a guitar tuner as a retirement present, which gets it close enough for folk music that I can take it from there.

Subject: RE: Hearing loss and tuning problems
From: Robert B. Waltz
Date: 05 Apr 26 - 09:07 PM

Steve Shaw wrote: But (and to the point...) my sensitivity to out-of-tune playing, either by me or anyone else, has remained undiminished.

This is to be expected; indeed, loss of some frequencies may make it worse.

They've done some interesting research on how we hear and understand overtones. A string, or a blown cylinder, will have a tonic based on the length of the string/cylinder (I wish I could do diagrams here....) It will have a first overtone that is twice that frequency and half that wavelength (two cycles in the string length rather than one). It will have a second overtone with a third of the wavelength (three cycles in the string length), etc.

This is a sort of a natural chord: The tonic, a note an octave above that, and a fifth above that, and then another octave, and so on. (I don't remember all the notes, and I'm too lazy to work it out.)

The amazing thing about the brain is, if one of those overtones is left out, you are likely to "hear" it anyway. And this includes even the base tone. Play an A 110Hz with overtones (220Hz, 440Hz, etc.), and then subtract the 110Hz base note and people will still perceive the note that they're hearing as 110Hz, even though there is no actual 110Hz tone. It's as if the brain is doing a fast curve fit (or maybe some sort of a Fourier transform; I don't know) to "solve" for the correct note.

(I've noticed this myself. My hearing is generally good enough that I don't need hearing aids, but I seem to have a bit of a dropoff somewhere around 200Hz -- the G of an open G string. I have a little bit more trouble tuning to that G than to other notes. But I have no trouble perceiving a proper chord.)

The point is this: If you have lost a lot of hearing range, you're getting fewer data points to "solve" your equation. The sour notes -- the out-of-tune ones -- are likely to be more prominent and readily perceived, because they have less good sound to cover them up.

Subject: RE: Hearing loss and tuning problems
From: GUEST,Steve Shaw
Date: 05 Apr 26 - 08:20 PM

I too have high-frequency hearing loss, diagnosed 14 years ago when I went to have my severe tinnitus investigated. It's gradually getting worse. I've played the harmonica (of all ilks!) in sessions and bands for thirty years and ongoing. I've been obsessed in all that time with getting the fine tuning of my harmonicas "right" (i.e., compatible with the other fellas, most of whom are using cheapo tuners stuck on the ends of their guitars or whatever). Most harmonicas come in compromise tunings (something between just and equal temperament) that can easily sound out of tune with other instruments. You've all heard Bob Dylan, and, if you have a good ear, you've winced...

I've become very proficient at fine-tuning my harmonica reeds over the years. I still play in a gigging band and my harps are well-sorted these days. My hearing loss is now classified as mild-to-moderate, and I wear hearing aids.

I can't latch on to anyone playing ornate finger-picking and things like that, but I'm fine with, er, "strummers." But (and to the point...) my sensitivity to out-of-tune playing, either by me or anyone else, has remained undiminished.

This is a description of my personal experience only, and I do know that we're all different.

Subject: RE: Hearing loss and tuning problems
From: Black belt caterpillar wrestler
Date: 05 Apr 26 - 04:11 PM

If you ever get interested in how they predict tides there is a quite similar set of intricate bits of mathematics going on. This is also to do with harmonic frquencies.

We are all told that the tides are caused by the moon, but there is a smaller effect from the sun. This sets up a whole range of harmonic frequencies because of the two different length of time between the sun and the moon being overhead. There are some that have a large effect and some that are almost negligable.

Each body of water (or part body of water, such as a bay or an estuary) has a shape that enhances or decreases the effects of each harmonic frequency and so the height and time of high and low waters come out differently for different locations.

The last time I checked the Admiralty use 60 harmonic constants for the predictions for most places to get an accurate prediction. The next problem is tidal surges caused by atmospheric pressure pushing the water level down or raising it. After that there are influences from wind pushing the water sideways into estuaries etc. and if being "piled up" against the shore.

Robin (who used to produce the Admiralty Tide Tables a long time ago!)

Subject: RE: Hearing loss and tuning problems
From: Robert B. Waltz
Date: 05 Apr 26 - 03:57 PM

Mo the caller wrote: When the vibrations reach the cochlea, the fluid inside it moves. As the fluid moves it vibrates the hairs on the cells that line the cochlea. Each cell is stimulated by a particular note (or frequency) of sound

This is how the ear works. It isn't how hearing works. Hearing is an interpretation of what the ear hears.

Think about it. I'll have to use a guitar analogy rather than a recorder analogy because I don't know the recorder pitches, but anyway.... When one plays an A chord on a guitar (for instance), the G string (nominally) sounds a 220Hz A note, and the low E string sounds a 90Hz low E, and the high E string sounds a 359Hz E. But in addition, the G string also sounds (first harmonic) a 440 A, and the low E sounds (first harmonic) a 180Hz E, and the high E sounds (first harmonic) sounds a 758Hz E, and they also have second harmonics and there are the the other strings, too. A person with no hearing loss will likely have detectable levels of sound at fifteen to twenty different frequencies.

When you play an A chord, do you hear fifteen to twenty different frequencies, as if they were fifteen different lights on a Christmas tree string? No, you hear an A chord: A few notes in pleasant combination. That's the brain combining the signals from the ears.

This is, in effect, a mathematical calculation -- a complex summation. Now take out some of the high-frequency notes. Suddenly the sum isn't the same any more. This can, and does, affect the way the result sounds. On an instrument tuned on a natural scale, it would still sound in tune. On one using a tempered scale, no bets.

Subject: RE: Hearing loss and tuning problems
From: Mo the caller
Date: 05 Apr 26 - 03:31 PM

Interesting.
I've just tried Google. The only thing that seemed remotely relevant was an article that said that " When the vibrations reach the cochlea, the fluid inside it moves. As the fluid moves it vibrates the hairs on the cells that line the cochlea. Each cell is stimulated by a particular note (or frequency) of sound".

The other thing I've noticed is at our Dance Club. I don't always recognise the tune because I'm hearing the counter-melodies and harmonies.

And have they changed the BBC time signal or is it still the Westminster Chimes. Again I hear a harmony rather than the ding-dongs I expect.

Subject: RE: Hearing loss and tuning problems
From: Robert B. Waltz
Date: 05 Apr 26 - 03:02 PM

I believe it's the result of tempering. Any fixed-pitch instrument (e.g. something with strings and frets, or something with a sound tube and holes) has to be tempered rather than the true natural tone. (This is a particular problem on the B string of guitars, e.g.)

When you hear overtones or higher harmonies, that can cover up the effects of the tempering. But the overtones are higher-pitched than the base note. So a person who doesn't hear the high overtones will notice the wrong pitch.

I have no idea how one deals with it.

Subject: Hearing loss and tuning problems
From: Mo the caller
Date: 05 Apr 26 - 02:48 PM

I have a high frequency hearing loss. I have also noticed (but not quite believed) that CDs including high recorders sometimes sounded out of tune. I even bought a new descant recorder because I couldn't play mine in tune in the top octave.
Now I see on facebook that I'm not alone.
Anyone know anything about this?