Huh? Since When--?

[Bob Masta]

On Mon, 30 Jan 2012 16:05:42 -0800 (PST), Ron Hubbard
<orion@dslnorthwest.net> wrote:

Yeah, the screwdriver can't produce true torque-- it works mostly on a
resonance effect. Or rather, it would in the real world; in the Doctor
Who world it does medical scans, welds wire, cut out locks, and
everything else but make a proper cuppa tea.

Mine works at 13 kHz, a compromise frequency that I can hear but most
people have a problem hearing (I don't care *what* they say about the
upper limit for human hearing being 20 kHz, that's BS) but when
frequency modulated, they can hear the lowr secondary frequency.

That 20 kHz number is correct, but typically only for young
ears. Age in general, and especially an accumulation of
exposures to loud sound, can reduce it substantially.

About 25 years ago I was working with a hearing researcher,
who was trying to get his experimental setup working to
deliver 12 kHz tone bursts to an anaesthetized guinea pig in
a sound booth. I was standing at the equipment rack outside
the booth (door open) and could easily hear the tones. He
was pretty upset to discover that he couldn't hear the sound
even when he held the transducer near his ear.

Like I said, years ago. Dunno if I could still hear that!

Best regards,


Bob Masta

DAQARTA v6.02
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, Sound Level Meter
Frequency Counter, FREE Signal Generator
Pitch Track, Pitch-to-MIDI
Science with your sound card!

 

[Michael A. Terrell]

fungus wrote:

On Jan 28, 12:14 pm, "Michael A. Terrell" <mike.terr...@earthlink.net
wrote:
Jim Thompson wrote:

Michael A. Terrell wrote:

...30 feet off the floor. We had to use rolling scaffolding,

While some idiot decides the scaffolding is in their way,
and gives it a shove while you're up in the grid?


We're electronics guys. We know how to hook
up a 7000 volt tickler for people like that...

It's faster to just drop a 14" New Britan adjustable wrench on their
head.


--
You can't have a sense of humor, if you have no sense.

 

[Michael A. Terrell]

Bob Masta wrote:

On Mon, 30 Jan 2012 16:05:42 -0800 (PST), Ron Hubbard
orion@dslnorthwest.net> wrote:

Yeah, the screwdriver can't produce true torque-- it works mostly on a
resonance effect. Or rather, it would in the real world; in the Doctor
Who world it does medical scans, welds wire, cut out locks, and
everything else but make a proper cuppa tea.

Mine works at 13 kHz, a compromise frequency that I can hear but most
people have a problem hearing (I don't care *what* they say about the
upper limit for human hearing being 20 kHz, that's BS) but when
frequency modulated, they can hear the lowr secondary frequency.

That 20 kHz number is correct, but typically only for young
ears. Age in general, and especially an accumulation of
exposures to loud sound, can reduce it substantially.

About 25 years ago I was working with a hearing researcher,
who was trying to get his experimental setup working to
deliver 12 kHz tone bursts to an anaesthetized guinea pig in
a sound booth. I was standing at the equipment rack outside
the booth (door open) and could easily hear the tones. He
was pretty upset to discover that he couldn't hear the sound
even when he held the transducer near his ear.

Like I said, years ago. Dunno if I could still hear that!

I used to have no problem hearing the 15,734.34 Hz horizontal sweep
in cheap TVs and monitors.


--
You can't have a sense of humor, if you have no sense.

 

[krw@att.bizzzzzzzzzzzz]

On Tue, 31 Jan 2012 16:06:54 -0500, "Michael A. Terrell"
<mike.terrell@earthlink.net> wrote:

Bob Masta wrote:

On Mon, 30 Jan 2012 16:05:42 -0800 (PST), Ron Hubbard
orion@dslnorthwest.net> wrote:

Yeah, the screwdriver can't produce true torque-- it works mostly on a
resonance effect. Or rather, it would in the real world; in the Doctor
Who world it does medical scans, welds wire, cut out locks, and
everything else but make a proper cuppa tea.

Mine works at 13 kHz, a compromise frequency that I can hear but most
people have a problem hearing (I don't care *what* they say about the
upper limit for human hearing being 20 kHz, that's BS) but when
frequency modulated, they can hear the lowr secondary frequency.

That 20 kHz number is correct, but typically only for young
ears. Age in general, and especially an accumulation of
exposures to loud sound, can reduce it substantially.

About 25 years ago I was working with a hearing researcher,
who was trying to get his experimental setup working to
deliver 12 kHz tone bursts to an anaesthetized guinea pig in
a sound booth. I was standing at the equipment rack outside
the booth (door open) and could easily hear the tones. He
was pretty upset to discover that he couldn't hear the sound
even when he held the transducer near his ear.

Like I said, years ago. Dunno if I could still hear that!


I used to have no problem hearing the 15,734.34 Hz horizontal sweep
in cheap TVs and monitors.

I could hear them from the sidewalk in front of the house.

I worked with a guy (when I was in college) who said he could hear 30kHz, a
few years before(tested by the Navy). Later in the day we were working in the
same lab so without telling him I connected an oscillator to a speaker and
started playing with it around 25kHz. He could *easily* hear 25kHz and got
really pissed when he found out I was playing with him. It had been driving
him nuts for an hour.

 

[Ron Hubbard]

On Jan 31, 4:52 pm, "k...@att.bizzzzzzzzzzzz"
<k...@att.bizzzzzzzzzzzz> wrote:

On Tue, 31 Jan 2012 16:06:54 -0500, "Michael A. Terrell"





mike.terr...@earthlink.net> wrote:

Bob Masta wrote:

On Mon, 30 Jan 2012 16:05:42 -0800 (PST), Ron Hubbard
or...@dslnorthwest.net> wrote:

Yeah, the screwdriver can't produce true torque-- it works mostly on a
resonance effect. Or rather, it would in the real world; in the Doctor
Who world it does medical scans, welds wire, cut out locks, and
everything else but make a proper cuppa tea.

Mine works at 13 kHz, a compromise frequency that I can hear but most
people have a problem hearing (I don't care *what* they say about the
upper limit for human hearing being 20 kHz, that's BS) but when
frequency modulated, they can hear the lowr secondary frequency.

That 20 kHz number is correct, but typically only for young
ears.  Age in general, and especially an accumulation of
exposures to loud sound, can reduce it substantially.

About 25 years ago I was working with a hearing researcher,
who was trying to get his experimental setup working to
deliver 12 kHz tone bursts to an anaesthetized guinea pig in
a sound booth.  I was standing at the equipment rack outside
the booth (door open) and could easily hear the tones.  He
was pretty upset to discover that he couldn't hear the sound
even when he held the transducer near his ear.

Like I said, years ago.  Dunno if I could still hear that!

  I used to have no problem hearing the 15,734.34 Hz horizontal sweep
in cheap TVs and monitors.

I could hear them from the sidewalk in front of the house.

I worked with a guy (when I was in college) who said he could hear 30kHz, a
few years before(tested by the Navy).  Later in the day we were working in the
same lab so without telling him I connected an oscillator to a speaker and
started playing with it around 25kHz.  He could *easily* hear 25kHz and got
really pissed when he found out I was playing with him.  It had been driving
him nuts for an hour.- Hide quoted text -

- Show quoted text -

Some years ago they had this sci-fi show that did some really cool
experiments at the first opening of the show as a teaser-- stuff now a
days that you probably couldn't do becaus of an infinite number of
government regulations. Anyway, one of their best experiments [that
used sound] involved using a frequency generator connected to a
parabolic dish; when the tone got up into the ultrasonic, the
wallpaper at the other end of the room burst into flames! An
ultrasonic canon; so cool...

Ron