good luck with the device.Could be the fix.
It does sound like 2 issues to be dealt with
1/ over driven audio
2/ background noise
The overdriven audio should be dealt with with either a matching device or attenuation.
The apparent background noise could be a few different things.Overly sensitive mic, poor matching, circuitry derived noise for example
Remembering that an aircraft headset mic has a very close range (and noise cancelling in many types) so it wont pick up all the hash / noise generated in an aircraft cockpit.
Devices like your camera will have a mic more sensitive to more distance noises and also be sensitive to a greater range of audio frequency over a headset mic.
You generally need to close talk a headset mic to make them work nicely whereas a camera mic is an area mic similar to a cvr mic.
PS how were you affected by the Icelandic volcano ?
all the best from the other side of the world.