PsychPortAudioDataPixxTimingTest([waitTime = 1][, exactstart=1] [, deviceid=-1] [, latbias=0])
Test script for sound onset timing reliability and sound onset
latency of the
PsychPortAudio sound driver.
This script configures the driver for low latency and high timing
precision, then executes ten trials where it tries to emit a beep sound,
starting in exact sync to a black-white transition on the display.
You'll need measurement equipment to use this: A
DataPixx device from
VPixx technologies, connected to your computer via the USB connection
cable. Also a connection between the line-out jack of your soundcard and
the line-in jack of the
DataPixx to transmit the sound data. The
DataPixx
will receive the audio output of
PsychPortAudio/Your Soundcard, timestamp
it and send the computed timing data to your computer via USB.
Some parameters may need tweaking. Make sure you got the special driver
plugin as described in 'help
InitializePsychSound' for best results.
This is early alpha code, expect some rough edges...
'waitTime' = Time to wait (in seconds) before playing sound. Defaults
to 1 second if omitted.
'exactstart' = 0 -- Start immediately, measure absolute latency.
= 1 -- Test accuracy of scheduled sound onset. (Default)
'deviceid' = -1 -- Auto-select optimal device (Default).
'latbias' = Hardware inherent latency bias. To be determined by
measurement - allows to PA to correct for it if provided.
Unit is seconds. Defaults to zero.
Psychtoolbox/PsychTests/PsychPortAudioDataPixxTimingTest.m