On April 1, 2014, we had a DSC Alarm System installed. Upon checking the system, it appeared to be functioning okay. Immediately thereafter, the Keypad began to emit a faint but high pitch sound. And for a brief moment the sound would stop and the high pitch sound would resume again. The installer was not sure why the sound was occurring or understood its source. Why would this sound be emitting from the keypad? It's very annoying! Thanks