John Atkinson wrote:
"Arny Krueger" wrote in message
...

John Atkinson wrote:

I first would like him to clarify what spound pressure levels are
required for 6Hz to become audible.

No spound levels were involved.

On the chance that this was just another one of Atkinson's many careless
mistakes...

I would have thought it obvious that I was referring to _sound_
pressure levels.

I would have thought it obvious that I suspected that Atkinson was
referring to _sound_ pressure levels.

The sound levels involved were not extreme in any way. I did most of
the listening with Sony 7506 headphones and FSI IEMs. The signal
source clips at about 1.5 volts RMS, which sets a reasonably low
natural limit.

So, 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.

These are the widest range examples of those publications that I can find:

http://www.sengpielaudio.com/Fletche...son-Dadson.pdf

Fletcher-Munson seem limted to 25 Hz while Robinson-Dadson seem limited to
20 Hz.

Both Fletcher Munson and Robinson Dadson seem have be limited to audible
sounds.

There seems to be pretty good agreement that 6 Hz is infrasonic sound -
too low to be audible.

Yet, 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.
Since some other means of perception than hearing seems to be involved, it
may be unwise to go too far extrapolating this information about audible
sounds.