Sennheiser NoiseGard HMDC 322 Instructions For Use Manual page 68

Problem
Active noise compensation but
very low volume communication
Active noise compensation but
reduced intelligibility
Communications in one ear only
(only HMEC 300, HMEC 302,
HMEC 306 and HMEC 306)
Possible cause and what to do
The volume control is set too low.
Check the volume setting of the headset.
The headphone connection has been pulled out (except HMEC 305, HMEC 305-C and
HMEC 306).
Check to see if the headphone jack plug is correctly connected.
The microphone connection has been pulled out (except HMEC 305, HMEC 305-C and
HMEC 306).
Check to see if the microphone jack plug is correctly connected.
You are using a stereo intercom system but the headset is set to mono operation.
Set the Mono/Stereo switch to "Stereo".
You are receiving a mono source but the headset is set to stereo operation.
Set the Mono/Stereo switch to "Mono".
31