Date: Fri Aug 28 10:04:55 2009 Back to Contents ------------------------------------------------------------------------

Author: Pamela Dupuis

Subject: Re: Sound Bites


Audiologists have a device to test one's hearing through bone
conduction. It has a small piece that is held behind one's ear; feel the
spot with your fingers, the skull is just thinly covered there. It is
not new, so perhaps you might find an inexpensive older/used one.
Pj Dupuis

Daniel Kaplan wrote:
> I just came back from a vacation in London where I visited their
> Science museum. One of the exhibits would be cool to reproduce in my
> high school class as a demo that the students could "bite into". The
> demo consisted of a thin metal rod that was held horizontally at one
> end by some sort of apparatus. The workings of the apparatus were
> not visible.
> The user was told to unwrap a clean straw from a stack of available
> straws (they had special straws that were shorter than usual - I could
> have the student cut down a standard straw) and slide it over the rod.
> The next step was to put your fingers in your ears and bite on the
> straw. You could then clearly hear some local radio station.
> This is a great demo to show how sound is a transmitted vibration. To
> set this up I will need a mechanism to hold the rod quite stiffly but
> still be able to transmit vibrations to it. I was thinking I would
> try mounting a small speaker on a rod. Maybe if I remove the cone
> portion of the speaker I could get vibrations without too much sound.
> transmitted through the air.
> Does anyone have suggestions about how to accomplish this? Or has
> anyone built a similar demo that they could share some of the details?
> Thanks.
> Dr. Daniel Kaplan
> Physics Teacher
> Matawan Regional High School, Aberdeen, NJ

From Fri Aug 28 10:04:55 2009