Evening star. [volume] (Washington, D.C.) 1854-1972, 1908-09-04
PHOTOGRAPHS OF VOICES
THE PAROLOGRAPH AND ITS
NEW POSSIBILITIES.
How the Vowels and Consonants Are
Placed Upon the Sensitized Plate.
Characteristics Reproduced.
; Correspondence OF the London Mail.

Paris Correspondence OF the London Mail
Though the possibility of being able to
record on Photographic plate the vibra-
tons and sounds of the human voice has
long attracted the attention of scientists
the results of actual experiments in this
direction have hitherto been to some ex-
tent vague and unsatisfactory.
Undoubtedly the greatest progress to-
ward pholographing the voice had been
made by an English sayant. Duddell
who. / believe has actually succeeded
In obtaining on Photographic plate
number of waves or tracings which cor
respond more or less to certain vowels,
but owing to the 1nsufficiency of con-
tinuity in the vibrations photographed it
was found difficulty to recognize the
sounds by the waves or curves on the
Photographic plate.
Experimenting on the same lines as
Duddell. French engineer, NJ. Devaux
CharbOnnel of the government telegraph
and telephone department. has apparently
solved the problem as the result of an
interesting series of experiments which
were communicated to the French Acade-
my OF Sciences a few days ago.
After much research and many expert
ments M. Charbonnel has succeeded in
originating system whereby the charac-
teristicS of VowelS and conSonantS as ut
tered by the voice in front of a micro
phone attached TO an extremely sensitive
Blondel oscillograph. and placed in cir
cult between the micrOphone and an or
binary telephone battery, are transmitted
on to Photographic plate in the form of
a series of waves and curves as pro-
duced by the OscillatOr or Blondel oscillo-
graph. just mentioned. In other words
the waves of the voice sounds as they
pass through the microphone act upon
the extremely sensitive electric oScillator
and the movements or waves of this os-
cillator which possesses tiny mirror
lighted by an electric spark autOmati-
cally produced. throw upon the exposed
Photographic plate opposite the oscila-
tor the reproduction of the wave-like
movements.
Operation Simple.
Complicated as this explanation may
seem. the actual operation is simplicity
itself, and those who have seen the APP
paratus describe it as the pa rolograp phi.
from the French "parole," or word, or
Speech" though the inventor modestly
disclaims the use Of such word as be-
ing too pretentlous.
The possibilities opened up by the pa
Photograph" are many. When the instru-
ment Is sufficiently perfected there will
he little to prevent a telephone SUBJ
scriber from receiving message through
the telephone during his absence. The
spoken message will be photoRraphically
reproduced on an endless celuloid film
or other sensitive band and the subScrib-
er with a little practice. will DE able to
read il off. The difficulty in mastering
the Interpretation of the waves and
curves will. it is calculated, be no great
er than that experienced in acquiring
knowledge OF Pitman's shorthand.
In the course Of his experiments NJ.
Cha rbonnel has made Very curious dis
covery. 1t is that although the main fea-
lures OF the photographically repro
duced waves and curve remain the same
for each syllable, Yet no two persons give
exactly the same wave sounds In pro-
nnuncing the same syllable. For instance,
of twenty persons who pronounced the
vowei u through the microphone there
was in every case, a slight variation in
the wave lines geographically repro
! tuced from the oscillator, though 1t was
easy TO distinguish the essential char-
| acter;stics of the vowel "u.'
From this observation NJ Charbonnel
concludes that Mr.. Duddell is right when
| he says that the discovery Of a practical
| system of photographing the voice should
| prove of valuable assistance in helping
| to detect criminals. Just as no two per-
| sons thumb marks are alike. so no two
persons produce the same wave sounds,
| or rather, tones or "harmonics" Of wave
| sounds in pronouncinG any one OF the
| vCWels a. e, /, o, u. 1t will therefore
graph the wave sounds of the vowels
| produced by all persons who have under
gone conviction
Photograph in Evidence.
| 1t may be anticipated. too, that the
| "parolograph'' will play a conspicuous
part as a sort of silent witness in law
suits. for it is not at all necessary for a
person to speak through the telephone
| in order that hrs words may be repro
| duced and recorded with far greater GER
tainty than on a photographic cylinder.
A powerful microphone to which the pa
| rolograph'' is fitted, placed in the corner
| of an office. would silently and unobtru-
| sively reproduce and place beyond doubt
| a conversatio between two persOns-a
| verbal contract entered into. defama-
| tory statement made, etc, although Il
very long band of film would have to be
used and the expense would be very
/ great.
! In an interesting conversation which l