VxMark: Make rate change audio feedback similar to how volume feedback works

[carolinemodic]

Rate changes don't seem to have any audio feedback in mark/markscan. We should make it work like the volume changes where it only reads out if nothing else is being said but does provide some audio cue in that case.

Original Issue:
Not sure if this is an issue but we only run xmodmap properly on boot so if the ATI is plugged in after boot the volume up/down and rate change buttons do not work properly. The sound level is also different. When I was testing on the qa image I made 12-18-2025 at the atrium the rate change buttons did not work but the volume change buttons do. On my dev laptop it seems like the keys are mapping to what we expect so I'm not sure what the problem is in the QA image. The volume buttons DO work.

[carolinemodic]

The rate change is working in dev its just not saying anything over the audio that you changed rate. To test in atrium again in the new year but I think I likely was just confused testing there and not realizing the rate was changing.