The brain hears and adjusts to the sound we hear

[Lekha]

When you're listening to music anywhere, perhaps in that sweet spot, try turning around so that one ear is facing the speakers and the other is turned away. You'll notice that the sound (volume) you hear doesn't change. If you have a chair that swivels, you can turn around any way you like, and the sound you perceive remains the same. If you walk to a far corner of the room, parallel to the speakers, and then walk back along the same line to the other corner, crossing over that sweet spot, you'll hear the same volume of sound. I reckon the brain adjusts. It's the brain that does the hearing, not the ears. Ears are just the instruments the brain uses.

Your thoughts, please

(I tried this out in a somewhat smaller room, 4.2 metres by 3.8 metres. The speakers were placed along the longer wall, with the backs of the cabinets about 10 centimetres away from that wall. The speaker cabinets were standing on small, round tables with glass tops, and there was nothing underneath the glass. I tried this quite a few times.)

 

[DVDdoug]

There's SOME TRUTH to that but it's also true that most of the sound you hear is indirect-reflected, and the overall sound level doesn't change that much in different parts of the room. You could confirm that with an SPL meter.

Floyd Toole says:

...to claim that a smoothed steady-state room curve derived from an omnidirectional microphone is an adequate substitute for the timbral and spatial perceptions of two ears and a brain is absurd.

One ear alone isn't that directional. Two ears and your BRAIN analyzing loudness and timing differences help you to localize the source.

If you play a 10kHz test tone (which has a wavelength of 1.35 inches) you'll hear huge variations as you turn your head slightly or move around the room. That's the result of the soundwaves from the left & right speakers and the direct and reflected waves mixing and going in-and-out of phase. You can also measure that with an SPL meter. I was doing some higher-frequency experiments once with an SPL meter on a microphone stand and the readings were changing significantly as I moved-around behind the SPL meter and affecting the reflected waves.

At lower frequencies (say below 100Hz with longer wavelengths) you get similar effects but you have to move around the room more. But in this case it is usually noticeable with regular program material.

With regular program material which has many simultaneous and constantly-changing frequencies it's not as noticeable and the overall loudness isn't changing that much since some frequencies are in-phase where other frequencies are out-ot-phase.

 

[Lekha]

One ear alone isn't that directional. Two ears and your BRAIN analyzing loudness and timing differences help you to localize the source.

It's the brain that does the hearing, not the ears. Ears are just the instruments the brain uses. And the brain adjusts, so you hear what you want, or need to. The brain will never be a microphone.

 

[DSJR]

Tangential to this thread, but alongside our brains making up for all manner of things, try not using your rig for a few days or even a couple of weeks, then turn it on and play some music. Sometimes the sound is wonderful and it makes you so glad you have the gear that you have, but too many times it sounds awful until the brain kind-of corrects for this. Many UK based owners of certain systems in the past, used to put it down to the equipment warming up (yeah, all of twenty minutes usually), claiming that after cold-starts, their gear took WEEKS to fully come on song, where I suspect the time taken was their brains trying to adapt to an otherwise not so nice din

Our brains are wonderful things, but so easily fooled. Audio subjectivists who implicitly trust their ears and hearing acuity only, are fooling themselves frankly, but they'll deny it to their graves unless it's shown to them beyond any shadow of a doubt

 

[pma]

It's the brain that does the hearing, not the ears. Ears are just the instruments the brain uses

Of course. That is why there are no simple explanations and analogies with microphones.

 

[ZolaIII]

To our brain everything out of speach area is noise he really doesn't want to process if he doesn't have to. It does it on very high level if by any means it's new to him treating it as threat until it is sure it isn't one. When trained to a specific room or FR it identify it and doesn't do much processing. After it accommodate it self he switches to low processing mode and does the same to SPL level. Don't think for a moment it's not very precise ASP and can't be easily fooled by aded synthetic space (reverb).

 

[tmuikku]

Auditory system is wonderful!

I reckon the brain adjusts. It's the brain that does the hearing, not the ears. Ears are just the instruments the brain uses.

I think this is one of most important realizations one can do! Perception of sound that we have in our conscious mind is not sound that enters ear canal, but what the subconsious parts of brain, the auditory system, provides into existence, into perception! Reality we perceive is heavily "filtered" by our own brain and we have no direct control over it how it does it, it takes in sensory input and spits out perception for our consciousness.

I think that people far too often attribute sound to some gear, when in reality it's likely just how brain processes the sound. Auditory system is very much in the same signal chain as an amplifier or loudspeaker or room acoustics. It's the last link in chain before perception and filters everything.

So, if you are an audio enthusiast and want to perceive particular great sound, it would happen only when auditory system is aligned to provide that perception! And since we cannot consciously command our auditory system it can only be aligned indirectly, for example by changing listening position, getting bit closer or further from speakers. Quite simple, right, the gear and the room stays the same, but auditory system provides very different perception of stereo image in particular. And it's not only position, but all kinds of sensory input like sight and memories and so on.

When one realizes this, one can start doing listening tests to basically learn listen their own auditory system! We are not listening our gear, but our brain. This in turn opens up the whole listening skill game and provides understanding to notice when the perception is not what it is supposed to be, for example affected by bias or by adaptation. Very important stuff if one is after some particular sound.

I consider listening skill just ability to understand what we perceive and I think fooling around with this idea that we listen our own brain and doing all kinds of listening experiments with it really improves listening skill. And that improving listening skill is only way to make really great playback systems, and adjust and tune them so that auditory system gets aligned to provide perception we want to have.

 

[Sokel]

Talking about informed posts:

Bass and subwoofers

@bmc0 https://github.com/MalcolmSlaney/LoudnessModel This is a loudness model in Python (MATLAB link is included) by hearing researchers who represent the top of the academic field. Might help. In regard to loudness, there's this: https://www.aes-media.org/sections/pnw/pnwrecaps/2014/jj_jan2014/

www.audiosciencereview.com