They
worked closely with experts sound and hearing and made
several experimental machines that were used medical
research. The
West Orange laboratory had relinquished the production of
recorded cylinders (handing this over the Works), but
continued investigate the mysteries sound recording.
This work was carried out Walter Miller, under
Edison's constant supervision. They examined the human ear to
develop analogies between and the recording diaphragm.VII- 9
FINAL TRIUMPH THE PHONOGRAPH
After his European vacation 1889, Edison went back to
the drawing board and tried again turn his tinfoil idea into
a commercial machine. The 1890s were the real times of
"perfecting the phonograph" for Edison turned the unreliable
and over-complicated machine the 1880s into first class,
plain, practical machine" with mass market. The
development low-cost phonograph for amusement use had
begun 1890 when Edison started work several experimental
projects aimed producing phonograph that could recreate
the sound music. The three main elements this campaign,
improving the wax compound, cheap duplicating records, and
more realistic sound, were continued during the decade.-1 They examined every aspect sound understand
the different frequencies and changing tones recreated
