Frequencies covered by noise cancellation
"Harlan Messinger" wrote ...
Don Pearce wrote:
It is not a case of low frequencies being targeted, but really that
dealing with high frequencies is much more technically challenging. If
you really want good HF isolation, forget noise cancelling and buy
some passive ear defender types.
Really, it's more challenging? I would have thought one approach would be
applicable across the spectrum.
The fundamental theory is the same. But reconstructing a cancellation
signal at higher frequencies requires more processing horespower
(i.e. faster processors). And at shorter wavelengths it gets trickier
to deliver the exact cancellation waveform *at your eardrum* from
several mm away.
As Mr. Pearce suggests, passive isolation is still the more practical
way of dealing with HF noise toay.
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