This read-write Integer32 (-70 to -30 dBm) sets the signal level threshold used to detect Music On Hold on the interface, defaulting to -38 dBm. Administrators tune this threshold to control how the gateway distinguishes hold music from silence or normal speech, which affects features that behave differently when a caller is on hold. For example, if a MOH-triggered feature isn't activating on calls placed on hold, an admin might need to adjust this threshold to better match the actual loudness of the hold music being played.