soundStimuli demo does not work on El Capitan

Coding
1

The soundStimuli demo does not work on my Mac Pro (late 2013) under El Capitan. Any hint?

The output error is:

Using pysoundcard(with None) for sounds
Traceback (most recent call last):
File “/Applications/PsychoPy2.app/Contents/Resources/lib/python2.7/psychopy/demos/coder/stimuli/soundStimuli.py”, line 29, in
highA = sound.Sound(‘A’, octave=3, sampleRate=44100, secs=0.8, bits=8)
File “/Applications/PsychoPy2.app/Contents/Resources/lib/python2.7/psychopy/sound.py”, line 336, in init
self.setSound(value=value, secs=secs, octave=octave)
File “/Applications/PsychoPy2.app/Contents/Resources/lib/python2.7/psychopy/sound.py”, line 152, in setSound
hamming=hamming)
File “/Applications/PsychoPy2.app/Contents/Resources/lib/python2.7/psychopy/sound.py”, line 186, in _setSndFromNote
self._setSndFromFreq(thisFreq, secs, hamming=hamming)
File “/Applications/PsychoPy2.app/Contents/Resources/lib/python2.7/psychopy/sound.py”, line 200, in _setSndFromFreq
self._setSndFromArray(outArr)
File “/Applications/PsychoPy2.app/Contents/Resources/lib/python2.7/psychopy/sound.py”, line 438, in _setSndFromArray
callback=self._callbacks.fillBuffer)
File “/Applications/PsychoPy2.app/Contents/Resources/lib/python2.7/pysoundcard/pysoundcard.py”, line 668, in init
’input’, idevice, ichannels, idtype, ilatency, samplerate)
File “/Applications/PsychoPy2.app/Contents/Resources/lib/python2.7/pysoundcard/pysoundcard.py”, line 700, in _get_stream_parameters
info = device_info(device)
File “/Applications/PsychoPy2.app/Contents/Resources/lib/python2.7/pysoundcard/pysoundcard.py”, line 267, in device_info
raise RuntimeError(“Invalid device”)
RuntimeError: Invalid device

2

In preferences you can set different sound libraries. Try one of the others

3

Thanks a lot Jon. I could make it work by changing the default audio libraries in preferences [‘pysoundcard’,‘pygame’] to [‘pygame’]. If I try to change it to [‘pyo’] the experiment crashes with the following error message:

Fatal Python error: (pygame parachute) Segmentation Fault

Since I am working with multisensory temporal order judgments (flash / tone), I don’t know how bad I should want pyo to work, since the latencies are supposed to be lower than in pygame.

4

Give us some clues. What version of PsychoPy are you using?
The latest version of psychopy comes with a new back end “sounddevice” that seems to have excellent timing

5

I am using version 1.84.2 (for OSX 64bit). I guess you would suggest using the sounddevice module? I’ll try to give it a go and share the outcome.