Re: perception of circling horn (was: Doppler Effect Question)

["Paul O. Johnson" <pojhome@SWBELL.NET>]

----- Original Message -----
From: "Richard W. Tarara" <rtarara@SAINTMARYS.EDU>
To: <PHYS-L@lists.nau.edu>
Sent: Thursday, April 20, 2000 11:54 AM
Subject: Re: perception of circling horn (was: Doppler Effect Question)


To my question,

> Do we know the weighting our brains place on phase differences?

Richard replied,

> Quite a bit.  Try this experiment.  Take a stereo, wire the two speakers
correctly (in phase), separate them by about 10 feet, and
> then play a MONO source through both speakers (a voice works really well).
Stand midway between the speakers and back
> about 10 feet.  You will easily localize the sound as coming from between
the two speakers.  Now reverse the wires on ONE of
> the speakers.  The sound you now hear will be diffuse and without
particular direction.  [This was the phasing test I had on an old
> setup record.  A voice was recorded on both channels first in phase then
out.  The voice described what you should hear.  If you
> heard the opposite, your speakers were out of phase.]
>
> P.S.  The more standard phasing test for speakers (assuming your wires are
not color coded) is to place the two speakers close
> together, play music with considerable bass content, then reverse the
leads to one speaker.  The wiring with maximum perceived
> bass is the correct one.

An interesting demo, Richard, but is the answer to my question in there?
Viz, "What is the relative weighting our brain puts on time-of-arrival
differences, intensity differences, and phase differences when it localizes
a sound source?"

Paul