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[Scott Helmke]

Might this be because we disproportionately perceive the higher modes, which are inharmonically sharp, as the sound decays?

That's my best guess so far. If the fundamental drops out I definitely tend to notice the effect.  Happens on recordings most of the time.

[Lee Douglas]

Reminds me of listening to a familiar song on the radio out really low volume (barely audible) and then turning it up and realizing your brain has been "hearing" it in the wrong key the whole time!

[Art Welter]

There also is an installed sound system, that the laptop feeds via Bluetooth, with speakers high on one wall.

 Now and then, in the movie we were watching, there would be a bit of hard-panned foley, like someone slamming a door on one side of the room. This instantly blew the illusion with the sound coming from behind and one side. After they went back to talking the dialog would, in a sentence or two, revert to coming from the screen. Crazy thing the brain.

--Frank

Frank,

Our perception of sound location being directly "in front" or "behind" results from the reduction of high frequency sound entering the ear canals blocked in the "shadow" of the ear's pinna, while the shape of the pinna's convolutions creates vertical frequency related differences.

From what I've read, wireless Bluetooth has at least 32ms delay, so your brain must re-map the "too late" dual source audio to the moving lip "source" regardless of the actual sound coming from behind. The impulse response of the hard-panned single-source door slam gets the old "hunter (or hunted) brain" going again, as it stops believing the illusion and locates the source via L/R intra-aural time difference as well as the frequency response differences between the first arrival and room echos.

The hearing aids I'm using (Phonak-P90) have a latency of only around 6ms, quite low considering all the detection algorithm, EQ and dynamic processing with two A/D conversions. Now while riding my bike I can hear birds tweeting, but can't pinpoint their location unless I stop- the 6ms delay between the unamplified sound below 3kHz and amplified HF directly inserted in the ear canal messes up the brain's location mapping.

Fortunately, I'm not reliant on small bird hunting for my sustenance 

Art

[Keith Broughton]

There is a phenomenon with some wind instruments when overtones can be triggered by higher pressure playing.

So THAT's why the sax is always sharp
It really is interesting how the brain works with sound (and other sensory inputs) and if I had a life do over, I would go into the study of psychoacoustics.

[Mike Monte]

So THAT's why the sax is always sharp

When a sax player tunes it is done with a "straight tone" (no vibrato) firm embouchure.
When a sax player performs with vibrato it is usually done as a "jaw vibrato" where the player loosens and re-tightens his "embouchure" (jaw, mouth, lip grip on the mouthpiece) with each pulse.
The relaxing of the embouchure makes the pitch go flat at the bottom most part of the vibrato thus the overall pitch with vibrato will sound flat.  To compensate for this sax players usually tune a bit sharp so that when he/she uses vibrato the pitch is in the pocket (intonation-wise).
or
maybe it could be that the sax player you referenced is a hack  

[John Roberts {JR}]

So THAT's why the sax is always sharp
It really is interesting how the brain works with sound (and other sensory inputs) and if I had a life do over, I would go into the study of psychoacoustics.

The classic example is flute when played pianissimo (low volume) it makes a nearly pure sine wave, blow louder and generate more overtones.

JR

[Steve-White]

So THAT's why the sax is always sharp
It really is interesting how the brain works with sound (and other sensory inputs) and if I had a life do over, I would go into the study of psychoacoustics.

Which would have been a very fascinating career.

Allow me to add a twist to consider.  I've worked with German Shepherds in K9/Protection work since 1973.  At first it was about "training" and of course the capability of the dog itself.  Police, military or executive level personal protection work isn't something that's "trained into" that dog, it's developing the capabilities that the dog already possesses in large part and associating with commands.

Every dog is different, each develops in a unique fashion.  They are not trained automatons that follow commands.  There is a relationship and bond between handler and dog.  For instance doing a narcotics search or tracking we watch the dog's body language and know if it's "on" or "off" of the scent or trail.  As well when the dog alerts in a bite mode.  Always trust your dog.

What's the correlation to this topic?  Back to the trained dogs each being unique and not being an automaton that follows specific commands with fully predictable behaviors - yes when commanded to sit they sit.  But, when commanded "Find him" or "Find it" or "Seek" or "Get him" it's a whole different ball game - then the dog is somewhat on autopilot.

Over the years I've realized it's not just a "Trained Dog" you get - what you really get is access to the dogs faculties - hearing, scent, sight and aggression - they are an extension of the handler and the relationship is symbiotic.  It's amazing.  The team part, for example would be during a search for contraband in a building or area where the handler directs the dog where to look.  Or, when searching for a bad guy hiding or lost person to guide the dog into the wind for airborne scent.

Having access to a nose that's ~5000 times more acute than mine is quite an experience.

[John Roberts {JR}]

Over the years I've realized it's not just a "Trained Dog" you get - what you really get is access to the dogs faculties - hearing, scent, sight and aggression - they are an extension of the handler and the relationship is symbiotic.  It's amazing.  The team part, for example would be during a search for contraband in a building or area where the handler directs the dog where to look.  Or, when searching for a bad guy hiding or lost person to guide the dog into the wind for airborne scent.

Having access to a nose that's ~5000 times more acute than mine is quite an experience.

Dogs are now being used to detect covid with high 90 percentile accuracy.

JR

[Dave Garoutte]

Isn't "Weeep Weep Weeep" the Psycho acoustic effect?

[Steve-White]

Isn't "Weeep Weep Weeep" the Psycho acoustic effect?

Possibly more "Psycho" than acoustic...

[ProSoundWeb Community]