Re: spatial separation and ASA

[Ward Drennan <ward@xxxxxxxxxxxxx>]

> In other words,
> in cases where two signals were partially segregated by factor X,
> adding a difference in location would strengthen the segregation.

By separating spatially, you'll get a change in signal to noise ratio at
the two ears that will inevitably help. I think the work of Plomp (1976,
Acustica 34, 200-211) on speech intelligibility sheds some light on
this. In an anechoic environoment, spatial separation of two speech
sources gives a 5 dB advantage for speech intelligibility. If the
environment gets very echoic though, the advantage drops to 1 to 2 dB.
Note that head shadow plays a big role here. If you were to low-pass
filter the speech (limiting mostly to interaural timing cues), I bet the
advantage would drop to 2 or 3 dB in the anechoic and be non-existant in
reverberation.

Perhaps there are some more studies showing this? Speech has a number of
segregating cues, but can anyone point to more constrained studies that
show this, maybe with only one factor X?

>We know that spatial
> differences do play an important role in SEQUENTIAL grouping.).

Perhaps because of the integration of consitstant interaural cues over
time yeilding a clearer 'picture' of the scene?

> My point about spatial information was not that it was very weak
> but that it was only one of a number of cues for sound
> separation.  To this should be added the idea that it may need
> those other cues in order to be effective itself.
>
Yes, perhaps the human is better at Auditory SA than the machine,
because people are especially good at integrating all the information.

Best Regards,
Ward Drennan