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Subject: Re: Sound cancellation technology?
Date: Sun, 29 Dec 2002 04:03:22 +0000 (UTC)
NNTP-Posting-Date: Sun, 29 Dec 2002 04:03:22 +0000 (UTC)
User-Agent: tin/1.5.14-20020926 ("Soil") (UNIX) (Linux/2.4.19 (i686))
In sci.electronics.design Phil Allison wrote:
> wrote in message
>> In sci.electronics.design Phil Allison wrote:
>> > "Lady Liberty" wrote in message
>> > news:firstname.lastname@example.org...
>> >> How far along has sound cancelation technology come in the last 10
>> >> Can they use it to completely silence a bedroom area for sleeping, yet?
>> > It is still much cheaper to use sound proofing than electronics
>> > and that DOES cover the whole room.
>> Though soundproofing only the ears is cheaper still.
> ** That, unfortunately does NOT work.
> Sound enters the head via the nose and mouth as well as the ear
> canal, also through the bones of the skull.
> Any sound below a few hundred Hz goes around ear plugs like they are
> not there - in fact ear plugs make low frequency sound seem worse since any
> masking effects from mid and highs are gone.
> Been there, done that with 50 Hz tones caused by compressor motors
> bolted onto a common wall.
Earplugs don't have to be passive, and could get a few more db down,
especially if they don't have to cancel HF, which can be mostly killed by
http://inquisitor.i.am/ | mailto:email@example.com | Ian Stirling.
Windows 2000, software for next millenia. - Ian Stirling.
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