When you change programs or volume, etc, either via the hardware button or via the phone app, the HAs give a beep signal to signify the program change. Like 1 beep tone for program 1, 2 beep tones for program 2, etc. Or one short beep for volume up or volume down. Then there’s the start up chime as well. Or a series of beeps signifying a problem with the HAs, etc.
The beep signal frequency allows you to set this beep sound at either 750 Hz, 1 KHz or 1.5 KHz, and also the loudness level of the beep (Soft, Medium, Loud). For example, if you have worse hearing at 1.5 KHz than 750 Hz like mine, you’ll probably want to set the beep signal frequency at 750 Hz so you can hear the beep better at a lower frequency, even at the Soft beep volume. Otherwise, if I have my beep at 1.5 KHz even at the Loud beep volume, I may not hear it as well if I’m in a noisy place.
Below is the screenshot for the Philips HearSuite software showing the option to set the beep signal frequency and level at the bottom of the page. Your HCP can adjust this on the HearSuite software for you.