Re: [ARSCLIST] Not using headphones

[George Brock-Nannestad <pattac@xxxxxxxx>]

From: Patent Tactics, George Brock-Nannestad

Don Chichester asked:

> 
> Might this phenomenon also apply to those wearing hearing aids?
> 

----- yes, but many hearing aids act as compressors, which reduces the 
dynamic at the output to the ear. Modern hearing aids have individual 
compression in each frequency band, and the adjustment (both frequency band 
and compression ratio) is individual to the person, dependent on their 
losses. So this would confuse the issue, but I would think reduce the impact 
of the basic phenomenon.

----- while we are at hearing aids: if a frequency range has been lost, 
increasing amplification at that range would only aggravate that loss, so I 
would recommend (and live by, when the time comes) only using the hearing aid 
when it is needed for communication or survival.

Kind regards,


George

------------------------------------------------

> 
> In a message dated 8/26/2006 2:33:59 PM Eastern Daylight Time,  
> pattac@xxxxxxxx writes:
> 
> From:  Patent Tactics, George Brock-Nannestad
> 
> Dave Bradley  observed:
> 
> .............
> > 
> > I noticed years ago that when  I was removing headphones while the 
> > program was still playing that  there was a dopler-like shift in 
> > pitch. The shift stayed in place,  though, even when I held the 
> > headphones still. It seemed that the  distance affected the pitch, not the
> > motion of moving them away. I  have to wonder if there is something involved
> > on a smaller scale that  makes the sound slightly higher in pitch when it's
> > closer to the  ears. That might explain why people would sing not in tune
> > when using  headphones....
> 
> ----- this is a well-know phenomenon, at least by  acousticians. S. S. 
> Stevens 
> described this as early as 1948. We cannot  reproduce his graph here, and the
> curves are not linear, but let me read  some figures off it:
> 
> 5 kHz increases 6% in perceived pitch going from  50 to 90 dB
> 2 kHz is not much influenced
> 300 Hz decreases 6% in  perceived pitch going from 50 to 90 dB
> 
> (these percentages are about a  semitone!)
> 
> above and below these, the effects are more  marked.
> 
> This explains a lot of things, such as perceived distortion and  Dave's 
> observation.
> 
> Kind  regards,
> 
> 
> George
> 
> 
> 
> Might this phenomenon also apply to those wearing hearing aids?
> 
> Don Chichester