Question of Pitch Perception

[guyman]

I suffer from a small amount of tinnitus. Drumline, bands, loud concerts, and mixing- the tinnitus got real bad for a few years. It has improved as a I curbed drinking alcohol, lost some weight, and lived a more active lifestyle- and what I assume is just luck and time, because of the type of tinnitus it is. Really affected my mental health for a long time.
My heart truly goes out to anyone afflicted with tinnitus.

Take care of your ears kids !

[guyman]

I’ve not done any research into this, but I do know that my hearing system can tell me that very low notes can actually sound very out of tune, so much so that an ascending chromatic scale can actually sound in the wrong order, to me anyway.

In fact, I once thought I had a weird frequency fault and I had to actually check the pitches produced! I should mention this was using pure sine waves in an additive system. I only realised it was me when I added higher harmonics and then the notes sounded as expected.

So maybe we can all perceive low frequencies as musical pitches, but not necessarily accurately. That’s led me to think about pitch “resolution” at low frequencies. The difference between C1(note 24) and C#1 (note 25) is only about 1.9Hz. At higher pitches the Hz difference becomes much greater. For example, the difference between middle C and C# is over 15 Hz.

Ok closer to the topic at hand. Pitch perception.

I've been composing more electronic music again lately. At a more naive age, I really focused on how the bass felt and not the pitch being in key, mostly out of ignorance. That perception is colored by mood, and the speaker system the music is composed on. As I became wiser I began to pitch up the super deep "808" sine wave bass to make sure it is actually the correct melody due to blurry pitch perception, then pitching it back down once I'm certain.

Yet more recently I've started going back to going off of feel, detuning, not caring about the super low bass being totally in tune (we're talking 50hz and below). At that point the bass really starts to be more felt than heard- and if I want to saturate it to get harmonic over tones, or layer an octave up- I'm starting to go as far as cloning it, saturating, then filtering - so that the upper harmonics are in key, but the actual sub tone is whatever "feels right", even if it's "wrong". With kick like dance/hip hop/experimental whatever- I think that feeling of the bass becomes the priority. I do worry that if someone pitches the record up things could sound wonky, but how often will that dramatic of a pitch shift be important?

It's wild just how wrong I can be about a really low bass note, despite my trained ear. If everyone experiences a loss of perceptual resolution at the low end, how similar is our "wrongness" ? If I keep it out of tune for the feel, will someone else perceive it as out of key? Do they feel what I feel from that bass tone?

also.... Where is the valley of no perception? there seems to be in my experience a low oscillation dead zone when adding low sines to a master track, and I stop hearing or feeling them, then if I go lower I start to hear an LFO type feeling.

[Spogg]

Interesting thoughts. I put this into Google:

pitch perception and resolution at low frequencies

There’s a lot of interesting looking links, but I haven’t yet followed a single one!

[billv]

Free audiogram online ...https://hearingtest.online/

[tulamide]

resolution at low frequencies

This is the realm, where analog is superior to digital. Finite systems like our modern day AD/DA chips are reconstructing the gaps between two samples very good. But it is still reconstruction. Not the original data.

That's why I always laugh inside, when someone swears on analog gear, but then records it digitally.

However, Infrasound has properties, that go beyond hearing. For decades of decades, scientists thought, elephants would communicate producing infrasound with their body and listening to it with their big ears. It is only a few years now, that it was discovered (by observing two groups that lived several hundreds of kilometers apart), elephants have special receptors in their soles! They stomp on the ground, and the signals created this way are recieved hundreds of kilometers apart over their feet, recognizing the infrasound oscillations of the ground. Something that wouldn't be possible with sound within human range.

And so, when this one group discovered a water source, the leading mother informed the other group, which immediately changed course and they met 3 days later.

But the topc is pitch perception, you say? Yes, and I want to point out, that the stomping indicates that they do not percieve specific frequencies over their feet, but rather non-pitched sound, just like humans used drums to communicate over larger distances.

Because elephants do have the ability to percieve pitches. There's a famous guy who plays piano for elephants, and they come and stay for the whole performace, visibly enjoying it.

And to come back to my opening statement: at 1 Hz an infrasound wave has a length of 340m. It is not affected by any material, only distance makes the singal weaker. The resolution it would need to accurately record a 340m wavelength is not yet invented. But at such low movement, reconstruction algorithm fail and will create amplitude, where no amplitude exists or silence, where no silence exists.

Even with highly sensitive analog gauges, we can detect ultra-low infrasound only down to 5 Hz, and only if its amplitude is higher than 20 dB. Below 5 Hz, only with specific microbarometers as were invented to detect nuclear weapons tests.