A digital telecommunications system, a method of managing a communications network in such a system and a program product for managing audio transmission in a digital communications system. A softswitch manages communications between devices at network endpoints, e.g., session initiation protocol (SIP) devices, and detects when communications include a non-human, e.g., an audio system, at an endpoint. The softswitch selects conversational communications for calls between voice devices and messaging communications parameters with lower overhead for communications with an audio system, e.g., messaging systems such as voice mail.