Dynamic speech output configuration

Techniques are described for providing dynamically configured speech output, through which text data from a message is presented as speech output through a text-to-speech (TTS) engine that employs a voice profile to provide a machine-generated voice that approximates that of the sender of the message. The sender can also indicate the type of voice they would prefer the TTS engine use to render their text to a recipient, and the voice to be used can be specified in a sender's user profile, as a preference or attribute of the sending user. In some examples, the voice profile to be used can be indicated as metadata included in the message. A voice profile can specify voice attributes such as the tone, pitch, register, timbre, pacing, gender, accent, and so forth. A voice profile can be generated through a machine learning (ML) process.