Skip to content

jspsych-audio-slider-response

This plugin plays an audio file and allows the subject to respond by dragging a slider.

If the browser supports it, 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. If the browser does not support the WebAudio API, then the audio file is played with HTML5 audio.

Audio files can be automatically preloaded by jsPsych using the preload plugin. However, if you are using timeline variables or another dynamic method to specify the audio stimulus, then you will need to manually preload the audio.

The trial can end when the subject responds, or if the subject has failed to respond within a fixed length of time. You can also prevent the slider response from being made before the audio has finished playing.

Parameters

In addition to the parameters available in all plugins, this plugin accepts the following parameters. 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 audio file undefined Audio file to be played
labels array of strings [] Labels displayed at equidistant locations on the slider. For example, two labels will be placed at the ends of the slider. Three labels would place two at the ends and one in the middle. Four will place two at the ends, and the other two will be at 33% and 67% of the slider width.
button_label string 'Continue' Label of the button to end the trial.
min integer 0 Sets the minimum value of the slider
max integer 100 Sets the maximum value of the slider
slider_start integer 50 Sets the starting value of the slider
step integer 1 Sets the step of the slider. This is the smallest amount by which the slider can change.
slider_width integer null Set the width of the slider in pixels. If left null, then the width will be equal to the widest element in the display.
require_movement boolean false If true, the subject must move the slider before clicking the continue button.
prompt string null This string can contain HTML markup. Any content here will be displayed below the stimulus. 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).
trial_duration numeric null 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 subject's response will be recorded as null for the trial and the trial will end. If the value of this parameter is null, 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 trial_duration parameter). If false, then the trial will continue until the value for trial_duration is reached. You can set this parameter to false to force the subject to listen to the stimulus for a fixed amount of time, even if they respond before the time is complete.
response_allowed_while_playing boolean true If true, then responses are allowed while the audio is playing. If false, then the audio must finish playing before the slider is enabled and the trial can end via the next button click. Once the audio has played all the way through, the slider is enabled and a response is allowed (including while the audio is being re-played via on-screen playback controls).

Data Generated

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

Name Type Value
response numeric The numeric value of the slider.
rt numeric The time in milliseconds for the subject to make a response. The time is measured from when the stimulus first began playing until the subject's response.
stimulus string The path of the audio file that was played.
slider_start numeric The starting value of the slider.

Examples

A simple rating scale

var trial_1 = {
    type: 'audio-slider-response',
    stimulus: 'sound/speech_joke.mp3',
    labels: ['Not Funny', 'Funny'],
    prompt: '<p>How funny is the joke?</p>'
}