[plt-scheme] (clarification) Looking for Psychology lab applications

To clarify: I am wondering about functions that perhaps would let me 
provide frequency, volume, and duration arguments and would play a 
simple tone (at the given frequency, etc).

Just now I was successful at installing the sound teachpack identified 
for v.205 but it worked on 360 (under linux).  But as far as I can 
tell, it is designed to play pre-recorded sound files.  (At any rate, 
sound "can" work on linux.)

The larger context for my query would be a lab setting where a human 
subject is waiting for a stimulus (e.g. listening for a certain tone) 
and then presses a certain key upon detection of a particular stimulus. 
  The software controls timing of stimuli and records reaction time, 
etc.

Hope that clarifies some.  Thanks.
--Wayne