How to get the participant reaction time from audio

Programming Help
1

Hello, I seek guidance on how to accurately measure timing information of interchanging inputs from two participants. Specifically, participants will interchange their tapping on an external hardware device while listening to music. We want to know the timestamp of when each participant tapped in sync with the music and to each other. We are having difficulty determining the correct coding sequence to accomplish this goal. Can provide all necessary specifications of Matlab version and desktop where necessary. Thank you for your time and consideration.

2

You are being way too vague. Are you having trouble recording the sounds? Processing the sound? Knowing how recording timestamps relate to the recorded sound? etc

3

Thank you for your reply and apologies for the vagary. We do seek to know how recording timestamps relate to the recorded sound. Additionally, we seek how to label timestamps from two separate participant inputs relative to the recorded sound.

4

Writing here to clarify further. We seek code examples on how to get timestamps from keypresses in relation to the recorded sound, where the time stamps mark the exact time of audio playback. We also seek code for multiple near simultaneous keypresses.

5

Still needs more details about hardware, software, experimental setup etc.

And for up to 30 minutes of my time for more detailed advice from my side on this forum, paid support would be in order → `help PsychPaidSupportAndServices’.

A few free bread crumbs though:

  • KeyboardLatencyTest.m shows timed audio capture and response collection from different devices, comparing audio capture and keyboard/mouse/touchscreen/response box timestamps to evaluate timing precision of input devices via sound.
  • PsychPortAudioTimingTest.m demonstrates use of sound playback timestamps.
  • BasicSoundInputDemo.m also implements a voice-key with sound capture.
  • KbQueueDemo.m has stuff about keyboard timestamps.
  • Our ECVP-2013 Intro pdf file in PsychDocumentation/ folder to Psychtoolbox has some slides about the functioning of audio timing in PsychPortAudio.

Best
-mario