Twitter may have doubled the length of tweets in 2017, but sometimes even 280 characters are not enough to convey your message. Now, Twitter is adding another feature that will allow you to have voice tweets.
This possibility currently exists exclusively for Appliances with iOS and allows you to post voice messages to your tweets, like voice clips on WhatsApp or other messaging serviceschangeof messages. 
To use this mode, just tap the compose a new Tweet button and then tap the new sound button that appears at the bottom left. Tap the button and then tap “Done” when you're done.
https://twitter.com/Twitter/status/1273306563994845185
Voice clips are limited to 140 seconds. However, if you exceed the limit, Twitter automatically launches a new voice tweet and creates a new thread.
Voice tweets appear on your timeline with a large card like one video tweet. Audio does not play automatically. You have to tap the image to start.
