The media stream consists of the data exchanged during a call. TAPI only provides control for line and telephone devices and does not give access to media stream content. To manage the media stream, a Windows CE–based application can use other APIs, Wave Audio, or Media Control Interface (MCI).
In the same manner, the media stream in a speech call—where speech refers exclusively to human speech—is produced and controlled not by TAPI, but by one human talking to another. However, the line on which that call is established and monitored, and the call itself, remain in control of the TAPI application. Speech is considered to be any signal that can travel by way of a 3.1 kilohertz (kHz) channel.