20050228 (J)
Journal: February 28, 2005
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Senses (Deafness)

                                                                         FONIX Design
Ear piece – tuned for hard of hearing by resonance chambers. I noticed that holding my hand cupped behind my ear did almost as much to improve my hearing as amplified hearing aids. Half cone-shaped.

Resonance:    2” ≈ 5000 Hz
                       1” ≈ 10.000 Hz

@ 700 MPH (speed of sound)  = 12320”/sec
                                                  ≈ 10000”/sec

So one cycle (resonance distance):
       5000 Hz    ≈ 2”
       10000 Hz  ≈ 1”
       20000 Hz  ≈ ½ “

For example for 1" at 10000 Hz:
       V = f • λ    (10000”/sec=10000 cycles/sec x 1”)
       λ = V/f
       λ = 1”/cycle
       λ = 1”

So test for frequency is indicated in patients, then design FONIX to resonate at those frequencies and slip it over the ear. For a cardboard model made from a toilet paper spool the improvement over my cupped hand was significant. Better tuned and resonant material would be even better.


Journal entry for 20050306 on same topic inserted here

Speed of sound = 343 m/s
Hearing deficiency (mine at least) ≈ 1000 – 5000 Hz.
v = d/t
d=vt
343 cm/s x 1 cycle/5000s
λ = 34.3 cm to 6.86 cm from 1000 to 5000 Hz
λ = 6.86 cm to 3.43 cm from 5000 to 10000 Hz

FONIX wearable megaphone needs to have separations of multiples or fractions of these distances, tuned for hearing loss. (see FONIX 2/28 entry)