Facebook, Instagram, and WhatsApp have direct voice messaging on their app. Twitter is joining the team and will be testing its new voice recording soon. Twitter voice direct messaging will be first available for selected countries.
After Twitter release audio tweets for iOS in June, the company is now testing voice messaging through direct messages, and Brazil will be the first country to test the new development in place.
Product manager for direct messages at Twitter Alex Ackerman-Greenberg told The Verge that the company will be testing voice DMs soon.

We don’t know why Twitter only releases audio tweets for iOS but not for Android — and after three months the company wants to start testing voice direct messaging. We’re not even sure if this development will be available for all OS.