Another thought is to get some regular hearing protectors (about $20) and an
old set of headphones. Put the speaker from the headphones into the hearing
protectors (it's ok if the wire goes across the seal). That way they can hear
you (you may need an impedance matching plug). Then, they can use the regular
aircraft microphone (plugged into their microphone jack in the back) to talk to
you., Push to talk. It won't transmit from the back.

Jose

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