> For the complete documentation index, see [llms.txt](https://boinc-ai.gitbook.io/transformers.js/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://boinc-ai.gitbook.io/transformers.js/api-reference/utilities/audio.md).

# Audio

## utils/audio

Helper module for audio processing.

These functions and classes are only used internally, meaning an end-user shouldn’t need to access anything here.

* [utils/audio](https://huggingface.co/docs/transformers.js/api/utils/audio#module_utils/audio)
  * [`.read_audio(url, sampling_rate)`](https://huggingface.co/docs/transformers.js/api/utils/audio#module_utils/audio.read_audio) ⇒ `Promise.<Float32Array>`
    * [`~audio`](https://huggingface.co/docs/transformers.js/api/utils/audio#module_utils/audio.read_audio..audio) : `Float32Array`
  * [`.getMelFilters(sr, n_fft, n_mels)`](https://huggingface.co/docs/transformers.js/api/utils/audio#module_utils/audio.getMelFilters) ⇒ `Array.<Array<number>>`

***

### utils/audio.read\_audio(url, sampling\_rate) ⇒ \<code> Promise. < Float32Array > \</code>

Helper function to read audio from a path/URL.

**Kind**: static method of [`utils/audio`](https://huggingface.co/docs/transformers.js/api/utils/audio#module_utils/audio)\
**Returns**: `Promise.<Float32Array>` - The decoded audio as a `Float32Array`.

| Param          | Type              | Description                                       |
| -------------- | ----------------- | ------------------------------------------------- |
| url            | `string` \| `URL` | The path/URL to load the audio from.              |
| sampling\_rate | `number`          | The sampling rate to use when decoding the audio. |

***

#### read\_audio\~audio : \<code> Float32Array \</code>

**Kind**: inner property of [`read_audio`](https://huggingface.co/docs/transformers.js/api/utils/audio#module_utils/audio.read_audio)

***

### utils/audio.getMelFilters(sr, n\_fft, n\_mels) ⇒ \<code> Array. < Array < number > > \</code>

Creates a frequency bin conversion matrix used to obtain a mel spectrogram.

**Kind**: static method of [`utils/audio`](https://huggingface.co/docs/transformers.js/api/utils/audio#module_utils/audio)\
**Returns**: `Array.<Array<number>>` - Projection matrix to go from a spectrogram to a mel spectrogram.

| Param   | Type     | Description                                                                              |
| ------- | -------- | ---------------------------------------------------------------------------------------- |
| sr      | `number` | Sample rate of the audio waveform.                                                       |
| n\_fft  | `number` | Number of frequencies used to compute the spectrogram (should be the same as in `stft`). |
| n\_mels | `number` | Number of mel filters to generate.                                                       |