Audio Stimuli
Version: v1 (current)
Play audio content to participants for speech, music, or auditory perception research.
Overview
The Audio stimuli task plays an uploaded audio file using the HTML5 audio player. The native browser audio controls are always shown, so participants can play, pause, seek, and adjust volume. Playback interactions (play, pause, seek, ended) are recorded.
Common research uses include:
- Auditory memory: Listen to words or sounds for later recall
- Music psychology: Present musical excerpts for rating or analysis
- Speech perception: Play spoken stimuli for identification or discrimination tasks
- Auditory priming: Brief audio exposure before a target task
Where to Configure
Study form → Tasks → Stimuli tasks → Audio → Configure.
Configuration Parameters
The audio config exposes a small set of fields. There are no autoplay, volume, loop, or "require full playback" options in the config.
| Parameter | Type | Default | Description |
|---|---|---|---|
Audio file (stimuli_media_url) | string (uploaded URL) | '' | The audio file is uploaded (accept="audio/*"); the upload sets the media URL |
Main instructions (main_instructions) | string (HTML) | '' | Rich-text instructions shown with the task |
Hint instructions (hint_instructions) | string (HTML) | '' | Optional rich-text hint |
The serialized config also forces stimuli_type: 'audio' and includes the eight auto-generated task markers.
Participant Flow
- The audio player is displayed with native browser controls.
- The participant clicks play, and can pause, seek, or adjust volume using the controls.
- The Continue button is always enabled; the participant clicks it when ready to advance. (There is no enforced full-playback requirement.)
Design Recommendations
- Format: Use MP3 for maximum browser compatibility.
- Sample rate: 44.1 kHz sample rate is standard for research-quality audio.
- Volume normalization: Normalize loudness across all audio clips to ensure consistent presentation.
- Volume guidance: Provide participants with volume adjustment instructions before the task begins.
- Instructions: Use the main instructions to tell participants to listen to the full clip before continuing, since the Continue button is not blocked until playback ends.
Common Issues and Solutions
| Issue | Solution |
|---|---|
| Audio doesn't play | Re-upload the file; ensure the format is MP3; test on the target browser |
| Volume too loud or too quiet | Normalize loudness across files before uploading |
| Participants skip before listening | Add a clear instruction to listen to the full clip (full playback is not enforced) |
Data Output
Markers and Responses
Markers (stimulus_shown):
{
"type": "stimulus_shown",
"ts": "2024-01-01T00:00:01.000Z",
"hr": 1234.56,
"data": {
"type": "audio",
"url": "https://example.com/audio/clip.mp3"
}
}
Playback markers (media_play, media_pause, media_seek, media_ended) — emitted as the participant interacts with the player, each carrying the playback position:
{
"type": "media_play",
"ts": "2024-01-01T00:00:02.000Z",
"hr": 2234.56,
"data": {
"position_ms": 0
}
}
Markers (response_recorded):
{
"type": "response_recorded",
"ts": "2024-01-01T00:00:15.000Z",
"hr": 15234.56
}
Response Data:
{
"type": "audio",
"stimulus_url": "https://example.com/audio/clip.mp3",
"listening_time_ms": 14000,
"play_events": [
{ "type": "play", "position_ms": 0 },
{ "type": "ended", "position_ms": 14000 }
],
"completed_playback": true,
"responded": true
}
Summary Artifact
None. The audio stimulus task does not generate a summary artifact.
References
References depend on the specific auditory stimuli used. For general audio presentation:
- Foroni, F., & Semin, G. R. (2009). Language that puts you in touch with your bodily feelings: The multimodal responsiveness of affective expressions. Psychological Science, 20(8), 974-980.
Auditory stimuli databases:
- IADS: International Affective Digitized Sounds
- Speech Corpora: TIMIT, LibriSpeech