If there is a constant noise in the headset, which appears to be triggered by high pitch sounds, and a handset lifter is currently being used, it's most likely that a ringtone was not correctly recorded with the HSL 10.
Before proceeding with the steps below, if a ringtone was already recorded, we advise to unplug the ACC cable from the HSL 10 for 1 hour, this will perform a reset of the HSL 10.
1. Ensure that the microphone of the HSL 10 is correctly placed on the speaker of the deskphone by using either A or B (this depends where the speaker that emits a ringtone is located on the deskphone).
2. Proceed to record the ringtone of the deskphone with the HSL 10, this should be done in a quiet environment, as any other sounds will interfere with a correct recording of the ringtone.
3. If the ringtone can not be detected, proceed to change the pattern of the ringtone in the settings of the deskphone, if possible. Proceed to record the ringtone.