Re: [LAU] OT: Hearing high frequencies

have easy access to the engineering library where all these papers are stashed... The human ear has two physically discrete audio sensory mechanisms. A pitch-pased mechanism that finely distinguishes pure tones, and an 'energy' mechanism that responds much faster, mostly to impulses, with no tonal discrimination. These two mechanisms are reconciled in 'wetware', partly by backdating pure tone discrimination as the impulse/energy mechanism is much faster. These papers offered nerve potential measurements to illustrate the relative reaction speeds. The assertion was that pure tone discrimination ends around 20kHz, but that the impulse/energy mechanism is capable of sensing and integrating energy up to about a 100kHz bandlimit. There has also been some research of genetic gifts that grant pure tone discrimination well above 20kHz. It appears to be discrete genetic trait. I have always wondered if it ran in my family since I've always been able to 'hear' ultrasonic burglar alarms, though I've been losing that ability as I age. When I tested my own hearing for Vorbis-related research some time ago, my ATH and tonal perception curves appeared to be similar to the published numbers for typical individuals. Monty