Re: Random punter question of the night
I don't disagree with anything you are saying here, but I guess I don't understand the reason for this particular response. If you and Bennett like to listen to compression drivers at 1" from the driver then I stand corrected - I guess I didn't think it likely that people were routinely subjected to 150dB sound levels at venues in any quasi-normal non-Bennett listening positions. 
Ultrasound transducers run in the sound range that they do not because "that's just what happens", but because that's the pressure level needed to get a sufficient signal though the substantial attenuation of however much tissue is being examined. Presumably as the listening half of the transducer gets more sensitive with technology improvements, the SPL input will be able to be reduced, and since there is still some concern about the health effects of sonography, this will happen.
I agree with Jack - it's very difficult for me to see parents jeopardizing their children's hearing at tractor pulls, monster truck shows, concerts, etc.
