"Arny Krueger" wrote in message
...
John Atkinson wrote:
what sound pressure level was required for the 6Hz tone to become
audible? The Fletcher-Munson or Robinson-Dadson curves imply that 6Hz
is not audible at normal levels, yet you are saying different.

Please cite a reference that portrays minimum reliably perceptible
acoustic levels for the 5-10 Hz range from Fletcher-Munson
Robinson-Dadson, or any other source.

The sensitivity curves in these data increasingly rise with reducing
frequency to their lower limits. There is no reason to believe the
curves have points of inflection below those limits.

there is evidence that the absence, reduction or perhaps some other
kind of modification of sounds in the 6 Hz range can be reliably
perceived.

Not in the literature that I can find. In addition, there seems to be
agreement that perception of very low frequencies (though higher than
6Hz) involves the body rather than the ears. If so, how can you report
perceiving 6Hz tones using headphones? Was this a double-blind test
involving a high-pass filter? If so, then isn't it more likely that
the test was detecting the audio-band phase error of the filter,
rather than the presence of infrasonic (6Hz) information?

John Atkinson
Editor, Stereophile