Re: front to rear reversals

[mup1dm <mup1dm@xxxxxxxxxxxx>]

>Subject:     front to rear reversals
>Sent:        11/22/19 7:41 PM
>Received:    11/22/99 10:54 AM
>From:        Tim Cox, tcox@GEOPHY.CURTIN.EDU.AU
>To:          Auditory list, AUDITORY@LISTS.MCGILL.CA
>
>Dear List,
>
>I am presently making binaural recordings and attempting to stabilise the
>frontal imaging. Could anyone direct me to resources specifically related
>to solving this problem. Any thoughts on the phenomena?
>
>Tim Cox.
>
the most obvious reference -- check the bibliography in J. Blauert's
book "Spatial Hearing".

Much of the most recent work will be noted in the book "3-D Sound for
Virtual Reality and Multimedia Applications" by Durand R. Begault.

I have several thoughts on the phenomena, based upon my own
experiences in listening to binaural recordings:

- Different people are different; a recording that works well for
some may not be immersive for others.

- Playing the sum of the two channels from a front centre
loudspeaker can help to generate out-of-head localisation and help
to reduce the front-back reversal effect.

- "head tracking" really helps, if you can make it work in your
situation. Crossfade between recordings made at 5-degree intervals,
or in live situations use a motorised dummy head that moves with the
listener. Most stereophonic systems rely to some extent on our
"willing suspension of disbelief". In natural listening the
soundfield shifts when we move our head. (We hear a growling lion
to our left. As we turn counter-clockwise to face the lion, the
sound of the lion moves clockwise relative to our head.) In binaural
headphone listining the soundfield moves WITH the head. (as we turn
CCW, the sound of the lion moves CCW as well -- remaining FIXED
relative to our head.) This "unnatural" effect may be one cause of the
illusion breaking down.

Douglas McKinnie