Perhaps the pitch change is do to a "mini doppler effect sort of thing". Or too many beers. Peace,Barefoot

....I was going to say..in my pot smoking days, it always happened!, flat with low volume, sharp with higher volume.

Get a stroboconn or a pitch meter and see if it is just the lack of air (and support) creating it. Many if not all wind instruents if not properly played (and strings if not released properly) have a tendency to go flat during the decay. This is playing "103"

Their is a phenominon know as "absortion distortion" which is when the absorbtion coef. of the room exceeds the dynamic range of the sound pressure. Absorptive panels when soaking it up makes the ear/brain sense pitch change that is not actually there, but created, due to absorbed waves.

Lots can be said about this perception..I have studied some of this...still ongoing.

Glad you are noticing this. If artificially induced, (weed) this can account for more than 75% of it.

I noticed this sometimes too. Always disturbed me a little. Flat on low volume, sharp on high(and if I was high, I'd be lucky if I knew what key I was in) But try this to prove that the pitch didn't change, just your perception of it. Listen to a song that you know is in A440, and have your instrument tuned well to A440 also,in my case an un-amplified electric guitar. Now produce the effect by taking the headphones on and off. You'll notice your instrument stays in perfect tune with your percieved change in pitch. This phenomemon also bugged me out when listening to a low level bass guitar intro in a 50's type pop tune. When the vocals started, it sounded to me like the whole key transposed. Did anyone ever notice that ? It seems like the brain needs to hear a balance of high and low frequencies to be comfortable.

I would think that it's probably an element or two in the mix that is out of tune and at high level it's being masked by maybe harmonic content, as you drop the level, the harmonics drop to reveal more of the fundamental.

hey, sometimes I feel that too. I used to think that was due to too much high frequency damping ( too dry room) or if my ear was fatigued.
Does it have to do with doppler effect either?
:p:

I have never noticed this at low levels. But on a few gigs when the stage level has been ridiculously high I have felt that the bass (I'm a bass player) is pitched too high in comparison with the other instruments. And once when the level was insane it went as much as a semitone sharp (on the recording it was perfectly in tune). Extremely annoying, but also very interesting! (I'm a M.Sc. in physics as well. :s: )

Perception of intonation changes with volume. Perceived intervals expand as the volume increases and shrink as it goes down.

This means something that sounds in tune at a low level will sound like the higher note is sharp at high volume and something that sounds in-tune loud will sound like the higher note is flat at a lower volume.

This is why super loud headphone mixes can lead to flat vocals.

Bob is surely right! I have managed to avoid really high levels the last couple of years, and the memory is a deceitful thing... :d: