I work in a school, and we have a rewards program. Students are rewarded for practicing good behavior. One thing they are asked to do is not speak while the teacher is speaking. Also, when they are permitted to speak, they are asked to do so in an 'inside voice' (that is, not to scream or talk excessively loudly - which is referred to as 'outside voice' when done outside).
I would love to buy a device that could measure the frequency of their speaking out of turn throughout the day, and reward them when they comply with rules about when to speak and when to listen. In addition to that, I would live to reward them for speaking in a quiet tone when appropriate, and give them a visible 'indicator' (maybe an LED light) when they are speaking too loudly.
I know decibel meters are available for purchase, but without the functionality I describe.
Is there any such device available for purchase, with the features I've described ?
How might I hack together something that does this - best hardware and software to use ?