I'm so looking forward to reading your book, as this is perhaps the topic that is closest to my heart - so much so, that in the past I have spent quite some time writing research proposals around this subject. When I mentioned the announcement of this book to a colleague he asked "what are the resonant frequencies of our nearest sites?" (I live in N.Wales), to which I am unsure if studies have been undertaken. A national project quantifying each sites resonant frequencies would be such an addition to this area of research, and mixing this with a wider group of archaeo-acoustic and other multi-disciplinary researchers would be amazing. To this end if you, or anyone else are interested in following this further, or know of others who are already part way down the road then please get in touch!