1 / Check the sound level of the monitor
The monitor manages its own sound level. In the event of a sound reduction, check that the sound volume has not been changed: Adjusting the speaker volume
2 / Ensure that the street panel microphone is unobstructed
The street panel microphone is exposed to the weather and external inconveniences. It is necessary to make sure that it is not obstructed. For example, in some windy regions, dust can settle in the opening, or even small insects wanting to find refuge.
To remove any deposit in the microphone opening, blow into it or remove the obstruction (with the aid of a fine and pointed pick) carefully.