Sharp GX22 User Manual page 28

Muting the Dial Tone (DTMF Tone)
During a call, press A [Options] and press
1.
to highlight "DTMF Tones Off", then press
or A [Select].
To unmute the dial tone, highlight "DTMF Tones
On" in step 1.
Muting the Microphone
During a call, press C [Mute] to mute the
1.
microphone.
To unmute the microphone, press C [Unmute].
28 Call Functions
or