I'll leave it to you talking to Lisa in person sometime about "canceling" versus "masking" sound. She'll talk your head off about the subject, and I can't even begin to summarize what she has to say about it, other than to say that she gets very agitated about it.

Thanks for the reference about cranial osteopathy. There aren't any in northern Nevada (the only two that came up in the entire state are in the Las Vegas area) but there are a promising number in the Bay Area, so I'll talk to her about it and we might look into it further.