Yes, you can customize some beltpack functions with the onboard controls:(the table shows the options for the RS-601....RS-602 and RS-603 have similar options)        



To have the beltpack in listen only mode you can enable  Talk Disable --> Function 3This function turns the talk button on or off.When off, the talk button does not function.Turn the talk button off when you wish tooperate the beltpack as a listen-only device.To select “talk disable” for a channel:1. Press and hold the setup button until thesetup information window displays a “P” and then release thebutton.2. Repeatedly press the call button until “3” appearsin the display.3. Press the talk button to toggle “talkdisable” either on or off.The beltpack’s talk light reveals whether “talkdisable” is on or off. If the talk light is on, “talk disable” is on;if the talk light is off, is off.4. When you have made your selection, press the setupbutton to save it and to exit setup, or press the call buttonto select other functions to program.If you do not press a button within fiveseconds, the beltpack exits the setupprogram without making any changes.