Voicemail transcription is a popular feature of Google Voice. Having the ability to receive a transcript of a new voicemail by email or SMS and get a quick idea of what a voicemail is about, saves you time in deciding which voicemails are worth listening to.
Since transcription is fully automated and most people often don't talk in the same organized manner that they write, it is tricky to insert punctuation into a message. And reading long messages without punctuation can feel weird.
Today we made some more progress on transcript readability and launched an improved transcription engine with punctuation. Don't expect it to insert question marks for your callers' questions, but it should help make your message transcripts easier to read by breaking them into sentences separated by periods.
We hope you will like the improvement...
Google Voice Blog: Towards better transcription. Period.