Help with identifying sound

[VA3ADP]

Hello,

In my area, I have two local school bus companies, one is VHF simplex/duplex the other is UHF Repeatered. Both seem to have a similar noise when the dispatcher unkeys. I am generally curious if this is a foot pedal that is in use or some sort of desktop microphone. If anyone could potentially the sound and quite possibly the equipment being used (I know that is a long shot) that would be great.

I've attached the audio clips of both frequencies for comparison

Thank you

 

[Whiskey3JMC]

Buttons built into the mic generally make a clicking noise over the air when they're released whether it be desk mics, lapel/handheld mics, PTT buttons on the receiver itself. Might not hear it with a foot pedal or headset mic where the PTT is separate from the mic itself