Head movement

[Al Bregman <bregman@xxxxxxxxxxxxxxxxxxxx>]

Hi Pierre and List,

In addition, as you move your head, the change in amplitude in the high
frequencies, -- resulting from different positions of the ear relative to
the head's shadowing of the sound source -- will be different for sound
sources that are at different angles from the head.

Physically, the rotation of the head affects the sound in a similar way as
rotating the set of sound sources around the head.  However, we don't know
whether the efferent motor signal plays a role, in the case of voluntary
head movement.

Best wishes,

Al


----- Original Message ----- 
From: "Pierre Divenyi" <pdivenyi@xxxxxxxxx>
To: <AUDITORY@xxxxxxxxxxxxxxx>
Sent: Saturday, December 17, 2005 11:35 AM
Subject: : Sound Source Segregation and head motion


> Head motion temporarily changes a stationary source into a moving
> object. In the early 90's, Chandler and Grantham showed that the
> detectable angle of a moving object is inversely proportional to its
> bandwidth. In a theoretical paper** we showed that this trade-off is
> a property of physics -- in other words, motion changes spectral
> resolution and vice-versa. Consequently, by moving his/her head the
> listener can introduce subtle spectral cues that could be potentially
> useful for disambiguating spectral grouping of one or more
> simultaneously present sources.
>
> Pierre Divenyi
>
> **Divenyi, P. L. & Zakarauskas, P. (1992). "The effect of bandwidth
> on auditory localization: An estimation theory model", Auditory
> Physiology and Perception, edited by Cazals, Y., Demany, L. & Horner,
> K., (Pergamon Press, London) pp. 563-570.