Twitter started with a mere 140 characters per tweet—barely enough to work yourself into a lather. Little by little, Twitter has expanded the capacity of tweets by exempting images and boosting the character count to 280. Now, Twitter is expanding into spoken words. The iOS app will soon have support for recording your voice, and it will automatically run into multiple tweets.
The voice recording functionality is currently just for iOS, and only a few iOS users will get it at first. The option appears as a waveform button when composing a new tweet. Simply press that and start talking. Each tweet can contain 140 seconds of audio, but you can keep talking past that. The app will automatically add new tweets as needed to accommodate the recording. When listening to voice tweets, the app (again, iOS only) displays a playback bar at the bottom so you can keep scrolling through your timeline.
Twitter's availability plans are a bit vague, avoiding any specific mention of Android:
Creating voice Tweets will be available to a limited group of people on Twitter for iOS to start but in the coming weeks everyone on iOS should be able to Tweet with their voice.
We expect that voice tweets will appear in the Android Twitter client, but you won't have the bottom bar functionality or the option to create your own recordings. Twitter does not mention its plans for this feature on Android, but we have to assume voice recordings will become available eventually. For now, you'll just have to listen to your iOS friends talking on Twitter.