The Makus Valley Meter is an excellent tool for teachers, and does have positive impacts on students since a silent/reduced noise atmosphere is sometimes needed by students. It is one of the tools which I found most useful when I started teaching, and found great success with it prior to the COVID-19 pandemic.
The tool currently has issues with connotation that have become stronger with a return to physical learning. A survey of the elements of gamification I use in my classroom show it is the least enjoyed element, and labeled by over half my students as the most disliked. Many would prefer it removed or, at least, reworked in its current state. Explanations for disliking the element normally explained how it felt like a punishment for the Meter to be used.
A potential solution could to rework the mechanics of the Sound Meter. The Meter has a negative connotation of "we make noise, we are punished." Although it is a reward system, I can see how students see this perspective. The Meter starts with high level of winnable gold and XP, but over time there is no way to achieve more gold/XP. In fact, the longer the "game" is played by using the Meter, the more likely a failure is to happen! It does seem to go against the mindset we want to establish. Students should feel rewarded for using proper behavior, and though they ARE rewarded they feel the opposite.
A positive twist that still keeps the tool's function would be to make the tool "we stay quiet, we earn gold and XP!" I suggest that the Meter is set so that students can earn up to 'x' amount of gold after 'y' amount of time. Every period of time without interruption, the meter would slowly add more gold into the rewarded gold section. This shows clear growth for the behavior, and rewards students for longer periods of time without interruptions. The tool is pretty much the same as before; the only change is how the learning is presented. This would make the Meter seem like a goal or competition to earn as much gold as possible, rather than a dread for whether or not the gold on the screen will suddenly be halved.