> ## 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.

# Accent Detection

> Accent detection API — classify the speaker accent of an audio file, with a whole-file label and a per-window time series, in a single synchronous HTTP POST.

Accent Detection classifies the accent of the speech in an audio file from the voice signal. It returns a single whole-file `accent` label plus a time series of consecutive fixed-length windows, each with its own label. It is a pure classification endpoint — no transcript, diarization, or enrichment data is produced.

|                   | Batch                                                         |
| ----------------- | ------------------------------------------------------------- |
| **Use case**      | Classify the speaker accent of an audio file                  |
| **Protocol**      | HTTP POST                                                     |
| **Max file size** | 100 MB                                                        |
| **Output**        | Whole-file `accent` label + per-window time series            |
| **Options**       | `use_ensemble` for a more thorough analysis at higher latency |

Each `time_series` entry covers one fixed-length window, delimited by its `start_ms` and `duration_ms`; a trailing remainder shorter than one full window is omitted. A file shorter than one window returns an empty `time_series` — the whole-file `accent` label is always present.

<Note>
  If you need accent labels alongside a transcript, use the `accent_signal` enrichment on Multilingual Transcription instead — see [Transcription enrichment features](/guides/stt-enrichment-features#accent-detection).
</Note>

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).