I've worked in radio since the early 1980's, and have run into some unusual recordings in my professional life. but I don't have Clue One what to make of this item, courtesy Reuters via Yahoo! :
Are these people for real? A recording that can only be heard "by dogs"? How would you know if something was actually on the disc? [All right, there's probably a way to verify a recording. But are you getting Bowzer his own CD player?] After all, it is a charity recording, so who's going to worry too strenuously over whether there's actually anything there or not?
To be honest, the whole things reminds me of another "unheard" broadcast element that first popped up in the 1980's. Several radio stations, most of them in Canada if memory serves, claimed that they were broadcasting a special high-pitched sound [inaudible to humans, of course] that kept mosquitos away from the area around a properly tuned radio. Scientific research on the matter was "inconclusive", so life, and insect repelling techniques, moved on.
Another example of the "silence is golden" technique was presented by avant-guard composer John Cage in the early '60s. His "composition" 4"33 featured a pianist sitting and not playing the piano for the length of time in the title. Some mainstream composers said at the time they hoped for longer experimental works in the same vein!
As the story notes, the CD may soon be available in North America; till then, I'd hope a New Zealand reader of these musings [and there are a few of you, whether you want to admit it or not] could fill me in on how this all worked. Did your dog go spastic when the CD was on? Did he stop when it did? I'm going to lose sleep over this until I know. I just know I am! Or maybe it's the dogs howling along to that song I just can't hear...