WhatsApp is working on a new feature that will transcribe voice notes for users, so they don't have to listen to audio messages.
The feature was first spotted by WABetaInfo and is currently under development. Furthermore, the website notes that transcription will be done locally on the user's phone so Facebook will not have access to the audio recordings. The transcription, however, will be used by Apple to improve its speech recognition technology and is totally optional.
The transcribed messages will be stored locally so you can access them any time in the future without having to transcribe the message again. WhatsApp users can also jump to a specific timestamp if they don't need transcription for the whole message. Currently, the feature is in development for iOS users and there is no word on if or when the feature will be available for Android users. However, WhatsApp has a decent track record of bringing major features to both iOS and Android so we might see some solution for Android users in the future.
WhatsApp is expected to roll out the feature to iOS beta users in the near future. For now, there is no word on when the feature will start rolling out to WhatsApp for iOS users.