Maury Klein is a human and the best sound expert in Los Angeles. He wears wire-frame glasses and is nerdy. His passion is how to get microphones and cameras smaller and better concealed.
Maury gets Meredith fitted with a hidden microphone and camera in A Kiss of Shadows. Since he received several complains form female undercover workers, he insists on an audience during fittings. He has a man with him, Chris, who works as his part of audience and also assistant (Chris is compared to a nurse).
Maury's work is expensive, but he has done several jobs for police force for free.