Audio requirements
Details on audio requirements for sending requests to the APIs
Audio format
Our API currently accepts the following audio specifications:
| Audio format | WAV, MP3, M4A, OGG, WEBM |
| Sample rate | Minimum of 16Hz |
| Bit rate | Minimum of 16Bit |
| Audio channels | MONO or STEREO |
| Audio length | 30s (Pronunciation), 60s (Scripted), 120s (Unscripted) |
Recommended format
Our API will accept any of the formats documented above for ease of use, but for optimal performance and latency we strongly recommend that you send us your audio in the following format:
| Audio format | MP3 or WAV (MP3 will be smaller and faster over the network) |
| Sample rate | 16kHz |
| Bit rate | 16Bit |
| Audio channels | MONO |
| Audio length | 5 - 15 seconds (Pron & Scripted), 15 - 60 seconds (Unscripted) |
Base64 encoding
In order to send us your audio for assessment you will need to encode your recording as a base64 string, this is a way to encode the binary data of your audio and send it in an HTTP request.
Most programming languages have a built-in base64 encoding/decoding library. For testing purposes, you can use this online converter: https://base64.guru/converter/encode/audio