Run Psychtoolbox without sound

Hardware
1

We want to use the Eyelinktoolbox to present our stimuli on a ROG Zephyrus S17 gaming laptop running under ubuntu 18.04. Unfortunately, we cannot get any sound from our internal speakers, as ALSA is not configured for our Realtek ALC294 sound card. We can get sound over headphones.
When we try to calibrate our eye-tracker we get the following error message from octave:

“Expression ‘paInvalidSampleRate’ failed in ‘src/hostapi/alsa/pa_linux_alsa.c’, line: 2048
Expression ‘PaAlsaStreamComponent_InitialConfigure( &self->playback, outParams, self->primeBuffers, hwParamsPlayback, &realSr )’ failed in ‘src/hostapi/alsa/pa_linux_alsa.c’, line: 2722
Expression ‘PaAlsaStream_Configure( stream, inputParameters, outputParameters, sampleRate, framesPerBuffer, &inputLatency, &outputLatency, &hostBufferSizeMode )’ failedin ‘src/hostapi/alsa/pa_linux_alsa.c’, line: 2843”

Is it possible to run Psychtoolbox without it trying to ouput sound at all? Alternatively, can we configure our system so that we only use headphones to output sound?

2

Is it possible to run Psychtoolbox without it trying to ouput sound at all?

You could try (after El = EyelinkInitDefaults(winptr);)

El.targetbeep = 0;
El.feedbackbeep = 0;
EyelinkUpdateDefaults(El);

Hope this helps! Best,
Andreas

3

Yes. Thank you! It works with Octave.