Sound72private encrypted CDMA line. For this option towork correctly, you need to set the Voice Privacymenu (Menu 7-3-4) to Enhanced.Key Tone (Menu 4-6)In this menu, you can set up the sound yourphone generates when you press a key.The following options are available:Tone Volume: you can adjust the key tonevolume using the Navigation keys.Tone Length: you can select Long or ShortDTMF (Dual-tone Multi-frequency) tones. DTMFtones are sent by your phone to accessteleservices, such as a bank account. The systemused by the bank or other service determines ifyou need short or long DTMF tones. If the serviceis digital, as most are, short DTMF tones willalmost always work.Power On/Off Melody (Menu 4-7)You can activate or deactivate the tone that thephone sounds when it is switched on or off.2-Step Ringer (Menu 4-8)Use this menu to set whether or not the phoneuses the safety volume feature.On: the phone alerts you to incoming calls, alarmsand scheduler alarms using the lower level alertvolume for 2 seconds. Subsequently, the phoneuses the alert volume level you have set.Off: the phone alerts you to incoming calls,alarms and scheduler alarms using the alertvolume level you have set.