[Vintage-Audio] Re Frequency Behavior

Tue Jan 13 19:19:04 2004

Easy there Peter, thin skin can bring lurkers out of the woodwork.
Think how much damage can be done with a 15 K Hz "tone"
the same amplitude as say a 32 Hz.  Iz it real or iz it; what wuz
the brand of that tape, oh yeah, Memorex?

> [Original Message]
> From: Peter Markavage <[email protected]>
> To: <[email protected]>
> Date: 1/13/04 6:01:07 PM
> Subject: Re: [Vintage-Audio] Re Frequency Behavior
>
> Ok, I'll dance with you one more time.
> I wasn't having fun. I thought you were asking about the speed of sound
> at various tones and I told you. The speed of sound is not dependent on
> the frequency of the sound wave. Given the same starting point of the
> sound, the same amplitude, the same medium, and the same temperature, a
> 100 Hz tone, 1000 Hz tone, or 5000 Hz tone will all travel the same
> speed. Given that they travel the same distance, they all should hit the
> receiver at the same time. Obviously, the farther they travel, all tones
> will be proportionally weaker by the time they get to the receiver. How
> the receiver interprets these sounds, the receiver limitations, etc.
> would determine ultimately whether all tones would be heard. If you guys
> believe that  some frequencies, traveling the same distance, through the
> same medium, the same temperature, etc. are attenuated (high or low), I
> want to see the math for that
>
> Since you want to throw some credentials around, I  have a Master's in
> EE, major in physics, and minors in business and math. (chuckle, chuckle
> to you too)
>
> Pete, WA2CWA
>
> On Tue, 13 Jan 2004 12:07:24 -0500 "Duane Fischer, W8DBF"
> <[email protected]> writes:
> > Sheldon,         
> >         
> > Yes, on all points.         
> >         
> > Pete was having some fun throwing math equations around, but Pete, I 
> > have a
> > minor in mathematics from the University of Michigan, so be careful! 
> > You might
> > have to buy some new batteries for your calculator OM! 
> > (chuckle)                
> >         
> > Because I am blind, I know far more about what people hear, listen 
> > to, filter
> > out and so forth than anyone who is sighted. I use it every single 
> > day. A
> > sighted person learns 92% of everything visually. That means all of 
> > the other
> > senses, and there are far more than the five people think of, only 
> > 8% get used.
> > What is the greatest sense organ anyhow? The skin! What do we do? We 
> > cover most
> > of it up so its functionality is severely limited. Before we go down 
> > the path of
> > nudists ... Ha Ha.          
> >         
> > Bob? If you want to debate hearing, write me off list. Who was it 
> > that said:
> > "Everybody is talking, but nobody is saying anything?"         
> >         
> > DBF        
> >   
> >         
> > 
> > 
> > ----------
> > From: Sheldon Daitch <[email protected]>
> > To: [email protected]
> > Subject: Re: [Vintage-Audio] Re Frequency Behavior
> > Date: Tuesday, January 13, 2004 8:39 AM
> > 
> > Duane,
> > 
> > I think we may be in total agreement.  Maybe I wasn't quite as 
> > elegant in
> > writing.  The only part where I might disagree, in regards to radio
> > reception, is under the situation where next channel interference 
> > is
> > high enough, and the receiver has variable bandwidth filtering, so
> > that the higher audio frequencies are filtered out.  Depending on 
> > the
> > depth and shape of the filters, one could strip out most of the 
> > higher
> > audio frequencies, of a high pitched female announcer, and yet
> > still pass the lower frequencies of a heavy-bass announcer.  Under
> > this unique set of circumstances, you could make a case for
> > the lower audio frequencies.
> > 
> > Pete has a nice explanation of the speed of sound, but I think what 
> > he
> > overlooked is the attenuation factor of higher audio frequencies
> > vs lower audio frequencies.  I believe that was part of your 
> > concern,
> > wasn't it, range, not velocity.
> > 
> > Sheldon
> > 
> > "Duane Fischer, W8DBF" wrote:
> > 
> > > Sheldon,
> > >
> > > First, the human ear is trained from before an infant is born to 
> > listen in a
> > > specific frequency range for vocal patterns. Hence, humans focus 
> > on certain
> > > frequency ranges and filter out others without even realizing they 
> > are doing
> > so.
> > > A higher pitched voice tends to be heard above the general din of 
> > noise
> > > pollution we all experience in our daily comings and goings.
> > >
> > > The best example of this filtering I can think of, is that of a 
> > mother hearing
> > > her child several rooms away with a TV set going, people talking 
> > and all sorts
> > > of other racket. She hears the child whimpering and nobody else in 
> > the room
> > > hears a thing.
> > >
> > > The low note carries the greater distance because it has a longer 
> > wavelength.
> > > For instance, the kid down the street with the kickers in his 
> > trunk. You can
> > > hear the bass a quarter mile away, but nothing else.
> > >
> > > It was said that a female announcer on a radio station could be 
> > heard at a
> > > greater distance because of her high pitched voice. I disagreed. 
> > The radio
> > > signal carries only so far, regardless of what sex is doing the 
> > talking.
> > > However, because her voice is generally of a higher pitch it may 
> > be easier to
> > > hear because it is above the area of the general noise. So it 
> > 'appears that
> > she
> > > is heard farther away simply because the frequency of her voice is 
> > higher than
> > > the background noise.
> > >
> > > Your thoughts?
> > >
> > > DBF
> > >
> > > ----------
> > > From: Sheldon Daitch <[email protected]>
> > > To: [email protected]
> > > Subject: Re: [Vintage-Audio] Re Frequency Behavior
> > > Date: Monday, January 12, 2004 3:42 PM
> > >
> > > Duane,
> > >
> > > Maybe we are trying to compare apples and oranges here.
> > >
> > > In general, lower audio frequencies are attenuated less than
> > > higher frequencies, thus, you can hear the rumble of the loud
> > > bass much further away than the higher frequencies from the
> > > same boom box.
> > >
> > > When you get into the second part of your question, which
> > > announcer would be "heard" at a greater distance, assuming
> > > no interference, one would think there should be no
> > > difference in radio range, if that is the intent of your 
> > question.
> > >
> > > Now let's subject the signals to some interference, and
> > > then it becomes a little more difficult to answer, as the 
> > filtering
> > > necessary to reduce or eliminate the interference  might also
> > > be the same frequency range as the announcers voice.
> > >
> > > So now, at the RF side of the equation, I am at a loss for
> > > a definitive answer, as I think it might be a lot more
> > > subjective and related to the skills of the listener.
> > >
> > > More thoughts?
> > >
> > > Sheldon
> > >
> > > "Duane Fischer, W8DBF" wrote:
> > >
> > > >
> > > > Is it true that a higher note is often easier to hear, but a 
> > lower note
> > > travels
> > > > a greater distance?
> > > >
> > > > Now leaving the length of the sound wave out of the discussion 
> > momentarily,
> > > > given a male and a female announcer for a radio station, 
> > speaking at the
> > same
> > > > volume into the same mike, which signal will be heard at the 
> > greatest
> > > distance?
> > > > The one with the highest voice pitch or the one with the longest 
> > wave
> > length?
> > > >
> > > > Duane W8DBF
> > > >
>
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