When doing a remote Intercom to Voice Station (Keypad) or Door Station, the voice heard on the keypad is intermiitenltly loud then soft.
This is caused by feedback from the keypad/Door Station speaker to its own microphone. Comfort tries to compensate for the echo by reducing the speaker volume when the microphone picks up too much echo.
The remedy for this is to reduce the MIC gain using the trimmer next to the Comfort main board. The Door Stations and Keypads have their own trimmer. Turn anticlockwise to reduce gain. This whould allow stable volume on both ends
The setting of the trimmer depends on telephone line conditions depending on the location of the house so the factory default adjustment may not be optimium
Cuyech will come up with a guide to getting the best results from the Intercom in the near future