🚀 go-pugleaf

In article <3938@randvax.rand.org>, edhall@rand.org (Ed Hall) writes...
>In article <1992Oct29.092702.973@dxcern.cern.ch> jalocha@dxcern.cern.ch (Pawel Jalocha) writes:
>>I'm a beginner in DSP but if I were you I would just delay one signal
>>in respect to the other. No filtering, no amplitude change.
>>This is how human ears work - if the right ear hears a signal
>>advanced in respect too the left ear the brain assumes the signal
>>is coming from the right.
> 
>This is /one/ of the cues human ears use.  Amplitude difference is
>another, and tends to predominate in stereo reproduction.  Good thing,
>since controlling the position of your head relative to your loudspeakers
>with centimeter accuracy is a bit difficult!  But one of the reasons that
>binaural recordings played through headphones sound so realistic is the
>faithful reproduction of the interaural delays.
> 
>		-Ed Hall
>		edhall@rand.org

From my (non-expert) experience I would say the inter-aural delay is
dominant.

If you listen with earphones to a mono broadcast
and you move the "balance" potentiometer then
the sound "position" does move but not much really.

But record same sound on a tape, and while playing back on a stereo player
turn the magnetic head _just_ a bit (don't do it on a new player :-)
and you hear the source moves immediately right or left. You may check
after that the volumes in both ears are same but the sound
is not in front of you. This is because after you have turned
the stereo head it reads one tape track a bit delayed from the other.

About your head and the loudspeakers: When you move your head just
a centimeter the sound source _does_ move. You don't notice
it because you brain "knows" you moved your head and it "subtracts"
this movement and does not inform you about the apparent movement
of the source.

I agree that apart from inter-aural delay there is the amplitude
effect involved but trying to reproduce stereo effect with _only_
amplitudes does not work for me.

I really dislike stereo recordings made with "amplitude modify"
techniques. I recognize such technique is simple as it only involves
potentiometers but it's a shame today when you can have analog delay
lines (not to mention DSPs).

Remember I'm an amateur and my brain + ears may be different
from an average one :-)

Pawel