Re: Usefullness of portable-bodyworn noisegenerators.

From: <cont..._at_yahoo.co.uk>
Date: Fri, 09 Mar 2007 19:23:25 -0800

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From: cont..._at_yahoo.co.uk
To: "TSCM-L Professionals List" <TSCM-..._at_googlegroups.com>
Subject: Re: Usefullness of portable-bodyworn noisegenerators.
Date: Thu, 08 Mar 2007 18:47:29 -0800
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Hi Mark,

But my 30 $ sound software will notch-out any tone at the flip of a
switch
if there is another tone...i filter that out in the next go.
if there is another one i filter that also in the next go.

Ofcourse you can´t continue with that...since you will have nothing
left in the end.

Even a varying frequency could be followed and notched i suppose.

But interesting idea that is...so why not take your suggestion but
instead
of a single freq,dual freq,various frequencies separate the 2
ultrasounds with
as many frequncies as possible...wich would be NOISE !

In practice i would have to generate:

One 30 khz ultrasound tone

and

One 30 khz ultrasound tone...frequency-modulated with random pink
noise

According to your idea i would not hear nothing but the mic in the bug
will hear the difference wich is the pink noise.

Will that work ?


Also...
Will the ultrasound generator not do the same as the mic....at the
very
beginning of all of this ?
..meaning will the ultrasound emitting transducer not
also produce a tone at the difference of both frequencies ?

When i feed a ultrasound-transducer with 2 ultrasounds having a
difference of 1 khz...will that transducer not also emit a 1 khz
sound ?
if that is true..then there is no cone of silence but a 1 khz tone !



contranl




On 8 mrt, 21:25, marc k <gee..._at_yahoo.com> wrote:
> A better way might be the old "cone of silence" method-2 ultra sonic(at a=
t least above normal hearing frequencies) signals at the same time, with fr=
equencies about 1 Khz apart.
> Your ears will not hear it, but most microphones will, so they will pick =
up a 1 Khz beat note.
> This would work even better with maybe 5-6 frequencies, or one that sweep=
s around a bit(either would make it tougher to "notch out", of otherwise fi=
lter out the noise.
>
> The only possible problem I see, is that hearing aids will pick it up too=
.
>
> co..._at_yahoo.co.uk wrote:
>
> .
>
> Here´s another question from your online idiot...i´m pretty shure
> i won´t get a usefull answer...but that doesn´t matter since i´m
> actually
> talking to myself...while i´m doing that i usually find the answer
> myself.
>
> I´m thinking of having a small personal noisegenerator wich i would
> always
> carry with me...it would be easy to build something like that.
>
> What about the usefullness of a such a portable/bodyworn
> noisegenerator
> wich purpose would be to make it at least more difficult to bug my
> conversations with others...for example while i´m talking to someone
> at a restaurant table.
>
> >From what i read the whole idea of noisegenerators is that the level
>
> of noise
> is sufficient high that it will mask (overpower) the voices.
>
> So here´s the microphone of the bug.
> Here´s my voice.
> And here´s the noise.
>
> Lets assume as long as the bugs-mic receives more noise then voice
> ...my voice will be masked...fine ...that will work in general.
>
> Back to the restaurant
>
> How to accomplish above with my small portable unit...either by
>
> 1) Generating much louder noise then voice
>
> Undo-able in practice since i would have to produce so much noise
> that they will throw my out of the restaurant in less then 2 minutes
> remember that you don´t know where the bug is...it could be right
> at the table i´m sitting at.
> Also it will make the conversation itself impossible.
>
> or
>
> 2) Placing the noise-source much closer to the bugs-mic then my voice.
>
> Un-doable...since i don´t know where the bug is i can´t place my nois=
e
> generator
> closer to it in order to overpower my voice.
>
> One thing i know however is that the bug is not on me (lets hope so)
> but that doesn´t help much does it.
>
> So my idea of having a personal..or even better wearable-
> noisegenerator
> for protecting my own conversations can not work in practice.
>
> No need to reply..i´m using this group as a piece of paper to organise
> my
> thoughts
>
> contranl
>
> ---------------------------------
> Get your own web address.
> Have a HUGE year through Yahoo! Small Business.

Received on Sat Mar 02 2024 - 00:57:27 CST