Best mic setup for echoey labs

My third-period biology class meets in a very echoey lab, and I’m currently running a Phonak Roger Touchscreen Mic to the student’s receiver while interpreting, but when we rotate to four lab stations every 12 minutes, audibility drops and feedback creeps in. What portable speaker or mic placement tricks have worked for you to keep sound clean and hands free so students can focus on the signing without me chasing gear?

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I park the Roger Touchscreen flat at each station; ‘Small Group’ cuts echo — drop mic sensitivity one notch.

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