The <Play> verb plays an audio file back to the caller. Twilio retrieves the file from a URL that you provide.
The <Play> verb supports the following attributes that modify its behavior:
| Attribute Name | Allowed Values | Default Value |
|---|---|---|
| loop | integer >= 0 | 1 |
The 'loop' attribute specifies how many times the audio file is played.
The default behavior is to play the audio once.
Specifying '0' will cause the the <Play> verb to loop until the call is hung up.
Use it like so:
<?xml version="1.0" encoding="UTF-8"?>
<Response>
<Play loop="10">https://api.twilio.com/cowbell.mp3</Play>
</Response>
The "noun" of a TwiML verb is the stuff nested within the verb that's not a verb itself; it's the stuff the verb acts upon. These are the nouns for <Play>:
| Noun | Description |
|---|---|
| plain text | The URL of an audio file that Twilio will retrieve and play to the caller. |
Twilio supports the following audio MIME types for audio files retrieved by
the <Play> verb:
| MIME type | Description |
|---|---|
| audio/mpeg | mpeg layer 3 audio |
| audio/wav | wav format audio |
| audio/wave | wav format audio |
| audio/x-wav | wav format audio |
| audio/aiff | audio interchange file format |
| audio/x-aifc | audio interchange file format |
| audio/x-aiff | audio interchange file format |
| audio/x-gsm | GSM audio format |
| audio/gsm | GSM audio format |
| audio/ulaw | μ-law audio format |
You can't nest any verbs within <Play>. But you can nest <Play> within a <Gather> verb.
This TwiML document tells Twilio to download the cowbell.mp3 file and play the audio to the caller.
<?xml version="1.0" encoding="UTF-8" ?>
<Response>
<Play>https://api.twilio.com/cowbell.mp3</Play>
</Response>
Twilio will attempt to cache the audio file the first time it is played.
This means the first attempt may be slow to play due to the time
spent downloading the file from your remote server. Twilio may play
a processing sound while the file is being downloaded.
Twilio obeys standard HTTP caching headers. If you change a file already cached by Twilio, make sure your web server is sending the proper headers to inform us that the contents of the file have changed.
Audio played over the telephone network is transcoded to a format the telephone network understands. Regardless of the quality of the file you provide us, we will transcode so it plays correctly. This may result in lower quality because the telephone number does not support high bitrate audio.
High bitrate, lossy encoded files, such as 128kbps mp3 files, will take longer to transcode and potentially sound worse than files that are in lossless 8kbps formats. This is due to the inevitable degradation that occurs when converting from lossy compressed formats and the processing involved in converting from higher bit rates to low bit rates.