I hope Jason Rose sees this post. He has used a gopro around steam engines his fair share and home built a cool clamp style bracket for mounting. I do recall him saying that the 'water proof' case that seals the camera doesn't not transmit sound very well. There is another case with holes that allow for natural sounds to be recorded but that of course will not protect the camera as well as the sealed one.
Brian Jansky
Houston, Tx
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