Re: BMLD questions

[Erick Gallun <gallun@xxxxxx>]

At 11:43 AM 9/9/2005, Xuejing Sun wrote:
> Hello,
> I have a question regarding binaural masking level difference (BMLD). For
> NoSm condition, are there any studies that show the effect of varying
> noise level at the ear with signal? That is, keeping noise level on one
> side constant and varying the noise level on the other side (the signal
> side).
> Thanks,
> Xuejing
>  


 From Durlach and Colburn (1978), "Binaural Phenomena", in
Handbook of Perception

"detectability for (M|alpha(n), 0) [N0Sm with ILD applied to the
noise] is best when the noise in the ear not receiving the tone is at the
same level as in the ear with the tone; it decreases as the noise level
in the nonsignal ear becomes either smaller or greater than the noise
level in the signal ear."

They cite Egan, 1965; Weston and Miller, 1965; Dolan and Robinson, 1967
and McFadden, 1968.

This is not exactly what you asked about, but they say that changing the
overall level doesn't impact the size of the BMLD.  Consequently, it
shouldn't matter whether you are varying the level at the signal or
non-signal ear.  Monaural performance will vary, but the size of the
BMLD should not.

Erick Gallun
Postdoctoral Fellow
Hearing Research Center
Boston University
http://people.bu.edu/gallun