Depending on the carrier and the handset used, that can mean free-or, at least, much cheaper-calls to landline and mobile phones, as well as free voice and video calls between computers.

The audio quality of voice calls on any phone, through any carrier, seems to have gotten worse rather than better.

Nonlinguistic elements accompanying verbal words give a hand in communicating ideas, and it's a phenomenon in voice or body behaviors, a carrier of info-exchange.