Sending WhatsApp “Voice Notes” (audio play button appears in-app)
WhatsApp mobile users have the ability to record and send “Voice Notes” by holding a microphone button in the app. These appear as an audio message with a play button, rather than a downloadable file.
Businesses using the WhatsApp API for WhatsApp can send a Voice Note by using the OGG file format (with the opus audio codec – see above).
Only OGG files are natively playable in the WhatsApp app. Other audio formats supported by WhatsApp, such as MP3 files, will appear as a downloadable file in the app.