If you already have a logged in user and you want to prevent them from having to input their contact details again before submitting an audio message. Simply pass the unique identifier in a data attribute to the Soundbite widget. You can then sort by this in your messages interface.
<div data-soundbite data-soundbite-token="your-account-token" data-soundbite-userId="firstname.lastname@example.org"> </div>
When passing in the user information the widget will not ask for name and email address at confirmation prior to sending the message. It will send along the email address (or provided information) from your website.