Gigaset ION User Manual page 13

Call volume
During a call:
Press the Volume keys
for quieter, until the required volume is reached.
A signal sounds when the maximum or minimum volume is reached.
Muting the microphone
When the microphone is switched off, callers will no longer hear you.
During a call:
Press the microphone key
Cancelling muting:
Press the microphone key
on the right of the handset: at the top for louder and bottom
.
again.
Making calls
11