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From: murphy@gibbs.physics.purdue.edu (William J. Murphy)
Newsgroups: comp.sys.next
Subject: Controlling volume of audio presentations
Message-ID: <5091@dirac.physics.purdue.edu>
Date: 13 May 91 16:28:13 GMT
Sender: news@dirac.physics.purdue.edu
Organization: Purdue Univ. Physics Dept, W.Lafayette, IN
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I am considering writing a simple program which tracks the perception
threshold of an audio stimulus.  To do this, I want to implement the
Bekesy paradigm using the setvolume method in the sound kit.  To setvolume,
one supplies a floating point value between 0.0 and 1.0.  My question
is this, what are the granularity of the volume settings?  Typically,
one needs a dynamic range of -30 dB SPL to 90 dB SPL to characterize
normal thresholds and most hearing impaired.  

So, how fine of a control can be achieved with the NeXT's volume control?


Bill Murphy
murphy@physics.purdue.edu

West Lafayette, IN:  Where progress takes a back seat to tradition.