Twitter may have doubled the length of the tweets in 2017, but sometimes even 280 characters aren't enough to get your message across. Now, Twitter is adding another feature that will allow you to voice tweets.
This feature is currently exclusive to iOS devices and allows you to publish voice messages in your tweets, such as voice clips on WhatsApp or other messaging services. 
To use this feature, simply press the compose button for a new Tweet, and then press the new audio button shown at the bottom left. Press the button and then press "Finish" when 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 timeline you with a great card like a video tweet. Audio does not play automatically. You have to tap the image to start.
