Panasonic DBS-576HD Technical Manual page 259

Section 700 - Operation
• Voice Calling: Extension calls are connected immediately, without a ringing tone.
• Tone Calling: A ringing tone is sent to the called extension.
Extension Class of Service (COS) programming determines whether the default for the originating
extension is voice or tone calling. Regardless of the default, you can toggle between voice or tone
calling by entering the Tone-Voice Call feature code. For example, if the extension default is tone
calling, you can make a voice call to another extension by entering the Tone-Voice Call feature access
code.
576-50-700 DBS 576 (USA) issued September 2001
Chapter 6. DSLT Features
6-33