Hearing Bodily Functions (Super Sensative Micrphones):

[Josh]

I found out recently that the human body can produce minute audio. An
eyeball moving, an eye blinking, gastric sounds, a full bladder,
subvocalizations, heart beat, all these create sound, however minute.
What kind of microphone can pick these sounds up, and, more
importantly, does the microphone have to be in contact with the human
body to hear these things (I know NASA is using microphones sensitive
enough so that their crew can communicate commands via
subvocalizations. These microphones are attached to the neck, I
beleive)?

 

[Michael Black]

"Josh" (Hans2234@hotmail.com) writes:

I found out recently that the human body can produce minute audio. An
eyeball moving, an eye blinking, gastric sounds, a full bladder,
subvocalizations, heart beat, all these create sound, however minute.
What kind of microphone can pick these sounds up, and, more
importantly, does the microphone have to be in contact with the human
body to hear these things (I know NASA is using microphones sensitive
enough so that their crew can communicate commands via
subvocalizations. These microphones are attached to the neck, I
beleive)?

Your problem is likely going to be amplifying what you want, and not

amplifying what you don't want. Most of those things are relatively
quiet, and by the time you amplify them enough so you can hear them,
external sounds will get quite loud.

In other words, if you turn up your hearing aid volume in order to
hear the person next to you who is barely speaking, the frogs outside
may be way too loud.

Michael

 

[Kim Sleep]

Eye Billy...you wont need any new-fangled, super sensitive microphone to
hear most of MY bodily functions!!
--
Kim..."A Man Of True Frankenstinean Proportions"

"Josh" <Hans2234@hotmail.com> wrote in message
news:1109387811.744626.223990@l41g2000cwc.googlegroups.com...

I found out recently that the human body can produce minute audio. An
eyeball moving, an eye blinking, gastric sounds, a full bladder,
subvocalizations, heart beat, all these create sound, however minute.
What kind of microphone can pick these sounds up, and, more
importantly, does the microphone have to be in contact with the human
body to hear these things (I know NASA is using microphones sensitive
enough so that their crew can communicate commands via
subvocalizations. These microphones are attached to the neck, I
beleive)?

 

[Josh]

Do you know how much $ Piezo disks can go for?

 

[Doug McLaren]

In article <cvp2a6$gu$1@theodyn.ncf.ca>,
Michael Black <et472@FreeNet.Carleton.CA> wrote:

| Your problem is likely going to be amplifying what you want, and not
| amplifying what you don't want. Most of those things are relatively
| quiet, and by the time you amplify them enough so you can hear them,
| external sounds will get quite loud.

Another problem is that the sounds generated by many of these things
is less than 20 Hz, and your ear just can't hear much below that.
I've heard it suggested that these noises are exactly why your ears
can't really hear below 20 Hz -- that it's a `survival of the fittest'
thing, that those who could hear below that basically had reduced
hearing, because they kept hearing noises generated by their own
bodies) and so they were less likely to pass on their genes ...

(Now, there may be harmonics at higher frequencies, and those may be a
high enough frequency to hear, but then they're so weak that it's what
Michael said.

--
Doug McLaren, dougmc@frenzy.com
You can tune a piano, but you can't tuna fish.
You can tune a filesystem, but you can't tuna fish.
-- from the tunefs(8) man page

 

[Daniel Watman]

"Michael Black" <et472@FreeNet.Carleton.CA> wrote in message
news:cvp2a6$gu$1@theodyn.ncf.ca...

"Josh" (Hans2234@hotmail.com) writes:
I found out recently that the human body can produce minute audio. An
eyeball moving, an eye blinking, gastric sounds, a full bladder,
subvocalizations, heart beat, all these create sound, however minute.
What kind of microphone can pick these sounds up, and, more
importantly, does the microphone have to be in contact with the human
body to hear these things (I know NASA is using microphones sensitive
enough so that their crew can communicate commands via
subvocalizations. These microphones are attached to the neck, I
beleive)?

Your problem is likely going to be amplifying what you want, and not
amplifying what you don't want. Most of those things are relatively
quiet, and by the time you amplify them enough so you can hear them,
external sounds will get quite loud.

In other words, if you turn up your hearing aid volume in order to
hear the person next to you who is barely speaking, the frogs outside
may be way too loud.

Michael

I read somewhere (but have not tried) that a piezo disc taped to the body
works well. This should be far more sensitive to internal sounds compared to
external sounds (like a stethoscope). What you can pick up will then depend
on your amplification, as Michael said.

-Daniel