On 10/03/2015 15:10, Jim Lesurf wrote:
In article , Don Pearce
wrote:

Played by itself, people couldn't hear the 'ultrasound'. But their
brainscans were different with/without it when the main music was
played.

So it seems possible that high frequency tones which are - in isolation
- 'inaudible' may affect our perception when they accompany clearly
audible lower frequency sounds.


I think a likely explanation is the simple non-linearity of the ear
causing audible intermod products when the ultrasonics were on.

Agreed. Which in turn implies that the sound *level* may matter. i.e. Any
such impact on the 'perceived sound quality' may only occur when the sound
level at the ears is loud enough. Which may indicate why some people notice
and care whilst others don't - even if using the same kit and having
'similar ears' in conventional hearing tests.


These threads feel like some kind of altered reality. Sound is
experienced in all manner of ways - not just through ears.

Honestly, you boffins. Surprised we get anything done with you lot
pushing the buttons :-)

--
Cheers, Rob