jspsych-single-audio plugin

This plugin plays audio files and records responses generated with the keyboard.

Audio files are played using the WebAudio API. This allows for reasonably precise timing of the playback. The timing of responses generated is measured against the WebAudio specific clock, improving the measurement of response times.

Audio files are automatically preloaded by jsPsych.

Parameters

This table lists the parameters associated with this plugin. Parameters with a default value of undefined must be specified. Other parameters can be left unspecified if the default value is acceptable.

Parameter Type Default Value Description
stimulus string undefined Path to an audio file.
choices array [ ] This array contains the keys that the subject is allowed to press in order to respond to the stimulus. Keys can be specified as their numeric key code or as characters (e.g. 'a', 'q'). The default value of an empty array means that all keys will be accepted as valid responses.
prompt string "" This string can contain HTML markup. Any content here will be displayed on the screen. The intention is that it can be used to provide a reminder about the action the subject is supposed to take (e.g. which key to press).
timing_response numeric -1 How long to wait for the subject to make a response before ending the trial in milliseconds. If the subject fails to make a response before this timer is reached, the the subject's response will be recorded as -1 for the trial and the trial will end. If the value of this parameter is -1, then the trial will wait for a response indefinitely.
response_ends_trial boolean true If true, then the trial will end whenever the subject makes a response (assuming they make their response before the cutoff specified by the timing_response parameter). If false, then the trial will continue until the value for timing_response is reached. You can use this parameter to force the subject to view a stimulus for a fixed amount of time, even if they respond before the time is complete.

Data Generated

In addition to the default data collected by all plugins, this plugin collects the following data for each trial.

Name Type Value
stimulus string The path to the file that was played during the trial.
key_press numeric Indicates which key the subject pressed. The value is the numeric key code corresponding to the subject's response.
rt numeric The response time in milliseconds for the subject to make a response. The time is measured from when the audio file began playing.

Examples

Playing a sound

var trial = {
    type: 'single-audio',
    stimulus: 'sound/sound.mp3'
}

Restricting which keys the subject can use to respond

var trial = {
    type: 'single-audio',
    stimulus: 'sound/sound.mp3',
    choices: ['h','s']
}