> ## Documentation Index
> Fetch the complete documentation index at: https://docs.modulate.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Audio Event Detection

> Audio event detection API — score an audio file against a fixed set of non-speech sound events in a single synchronous HTTP POST.

Audio Event Detection scores an audio file against a fixed vocabulary of 42 non-speech sound events: instruments, human vocalizations such as laughter and coughing, and environmental noises such as a knock or a gunshot. It returns a probability for each event it confidently detected, plus the duration of the processed audio. It is a pure classification endpoint, producing no transcript, diarization, or PII/PHI tagging.

| | Batch |
| - | - |
| **Use case** | Detect which non-speech sound events are present in an audio file |
| **Protocol** | HTTP POST |
| **Max file size** | 100 MB |
| **Output** | A probability per detected event, plus `duration_ms` |
| **Options** | None. Only `upload_file` is accepted |

`probs` carries one entry per confidently detected event, drawn from a vocabulary of 42, and is an empty object when nothing was detected. Entries are independent probabilities: they are not mutually exclusive and are not expected to sum to 1, so each is thresholded on its own. An omitted event was not detected with sufficient confidence, which is not the same as it being absent from the audio. See [Audio Event Detection](/get-started/audio-event-detection).

For a side-by-side comparison with the other Modulate capabilities, see [Which API should I use?](/guides/which-api).

## Authentication

Uses the `X-API-Key` header. See [Authentication and rate limits](/guides/authentication).


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.