NMSAT :: Networked Music & SoundArt Timeline

1878 __ The Talking Phonograph
Thomas Alva Edison (1847-1931)
Comment : “Mr. Thomas A. Edison recently came into this office, placed a little machine on our desk, turned a crank, and the machine inquired as to our health, asked how we liked the phonograph, informed us that it was very well, and bid us a cordial good night. These remarks were not only perfectly audible to ourselves, but to a dozen or more persons gathered around, and they were produced by the aid of no other mechanism than the simple little contrivance explained and illustrated (in this paper). The principle on which the machine operates we explained quite fully in announcing the discovery. There is, first, a mouthpiece A, across the inner orifice of which is a metal diaphragm, and to the center of this diaphragm is attached a point also of metal. B is a brass cylinder supported on a shaft which is screw-threaded and turns in a nut for a bearing, so that when the cylinder is caused to revolve by the crank C, it also has a horizontal travel in front of the mouthpiece A. It will be clear that the point on the metal diaphragm must, therefore, describe a spiral trace over the surface of the cylinder. On the latter is cut a spiral groove of like pitch to that on the shaft, and around the cylinder is attached a strip of tinfoil. When sounds are uttered in the mouthpiece A, the diaphragm is caused to vibrate and the point thereon is caused to make contacts with the tinfoil at the portion where the latter crosses the spiral groove. Hence, the foil, not being there backed by the solid metal of the cylinder, becomes indented, and these indentations are necessarily an exact record of the sounds which produced them. It might be said at this point the machine has already become a complete phonograph, or sound writer, but it yet remains to translate the remarks made. It should be remembered that the Marey and Rosapelly, the Scott, or the Barlow apparatus, which we recently described, proceed no further than this. Each has its own system of calligraphy, and after it has inscribed its peculiar sinuous lines it is still necessary to decipher them. Perhaps the best device of this kind ever contrived was the preparation of the human ear made by Dr. Clarence J. Blake, of Boston, for Professor Bell, the inventor of the telephone. This was simply the ear from an actual subject, suitably mounted, and having attached to its drum a straw, which made traces on a blackened rotating cylinder. The difference in the traces of the sounds uttered in the ear was very clearly shown. Now there is no doubt that by practice, and with the aid of a magnifier, it would be possible to read phonetically Mr. Edison’s record of dots and dashes, but he saves us that trouble by literally making it read itself. The distinction is the same as if, instead of perusing a book ourselves, we drop it into a machine, set the latter in motion, and behold ! The voice of the author is heard repeating his own composition. The reading mechanism is nothing but another diaphragm held in the tube D on the opposite side of the machine, and a point of metal which is held against the tinfoil on the cylinder by a delicate spring. It makes no difference as to the vibrations produced, whether a nail moves over a file, or a file moves over a nail, and in the present instance it is the file or indented foil strip which moves, and the metal point is caused to vibrate as it is affected by the passage of the indentations. The vibrations, however, of this point must be precisely the same as those of the other point which made the indentations, and these vibrations, transmitted to a second membrane, must cause the latter to vibrate similar to the first membrane, and the result is a synthesis of the sounds which, in the beginning, we saw, as it were, analysed. In order that the machine may be able exactly to reproduce given sounds, it is necessary, first, that these sounds should be analysed into vibrations, and these registered accurately in the manner described; and second, that their reproduction should be accomplished in the same period of time in which they were made, for evidently this element of time is an important factor in the quality and nature of the tones. A sound which is composed of a certain number of vibrations per second is an octave above a sound which registers only half that number of vibrations in the same period. Consequently if the cylinder be rotated at a given speed while registering certain tones, it is necessary that it should be turned at precisely that same speed while reproducing them, else the tones will be expressed in entirely different notes of the scale, higher or lower than the normal note as the cylinder is turned faster or slower. To attain this result there must be a way of driving the cylinder while delivering the sound or speaking, at exactly the same rate as it ran while the sounds were being recorded, and this is perhaps best done by well-regulated clockwork. [...] Differences in velocity of rotation within moderate limits would by no means render the machine’s talking indistinguishable, but it would have the curious effect of possibly converting the high voice of a child into the deep bass of a man, or vice versa. No matter how familiar a person may be with modern machinery and its wonderful performances, or how clear in his mind the principle underlying this strange device may be, it is impossible to listen to the mechanical speech without his experiencing the idea that his senses are deceiving him. We have heard other talking machines. The Faber apparatus, for example, is a large affair as big as a parlour organ. It has a keyboard, rubber larynx and lips, and an immense amount of ingenious mechanism which combines to produce something like articulation in a single monotonous organ note. But here is a little affair of a few pieces of metal, set up roughly on an iron stand about a foot square, that talks in such a way, that, even if in its present imperfect form many words are not clearly distinguishable, there can be no doubt but that the inflections are those of nothing else than the human voice. When it becomes possible, as it doubtless will, to magnify the sound, the voices of such singers as Parepa and Titiens will not die with them, but will remain as long as the metal in which they may be embodied will last. The witness in court will find his own testimony repeated by a machine confronting him on cross-examination – the testator will repeat his last will and testament into the machine so that it will be reproduced in a way that will leave no question as to his devising capacity or sanity. It is already possible by ingenious optical contrivances to throw stereoscopic photographs of people on screens in full view of an audience. Add the talking phonograph to counterfeit their voices, and it would be difficult to carry the illusion of real presence much further.”. (Engineering, January 18, 1878 - reprint of an article from ‘Scientific American’)Contrary to received opinion, the phonograph actually originated in 1877 as a byproduct of Thomas Edison's unsuccessful plan to build a "keyboard talking telegraph," an instrument that would have allowed users to "play" individual speech sounds over a telephone line rather than speaking them into a mouthpiece. On May 26, 1877, Edison jotted down ideas for two inventions: (1) a spectrographic speech recorder based on the principle of the harmonic telegraph and (2) a "keyboard talking telegraph" that would synthesize speech sounds over a phone line using combinations of simple electrical breakwheels. - On July 11, 1877, his notes show that he'd concluded combinations of simple breakwheels wouldn't do, and that he now envisioned a separate wheel for each speech sound, containing variously spaced teeth of different heights. - On July 17-18, 1877, he apparently tried to figure out what patterns of teeth he'd need to create individual speech sounds by recording the actual vibrations of a telephone diaphragm, studying the records, and playing them back to verify what they represented. The results were inconclusive as far as visually recognizable patterns went, but he'd just discovered the principle of the phonograph. - Edison made technical mistakes and missteps throughout this period that he shouldn't have made if he'd known about the phonautograph -- so he probably didn't know about it during 1877, or at least didn't understand it. Edison did try to tell the "keyboard telephone" version of the story in an interview of April 1878 (quoted on p. 28). What we don't have is any statement of the circumstances under which Edison expected people to use either the keyboard telephone or the automatic (spectrographic) speech printer. (Patrick Feaster)Patrick Feaster mentions an interesting US patent, 474,230 (which contains material that was preserved (or paralleled) in Brit pat 2909). But 474,230 was only part of 2909, and the US application was "divided" (in 1877), finally yielding also 474,231 and 474,232. The former was executed on July 9th. Interestingly, it took 15 years to nurse the American version(s) thru the patent system, and those 3 were not granted until 1892. It would be very helpful to acquire the contents of their Patent Wrappers (contents) from the National Archives, as the preserved correspondence and adjustments would reveal what caused the conflicting issues (and long delay). Brit Pat 2909 had its own share of problems for Edison, as it started out as a telephone patent when it was filed, but was wrongheadedly used by Edison to introduce his tinfoil phonograph (in England) during its period of application (fig. 29 added). Eventually (1882), this attempt was disavowed by him, and the phonographic portion was removed. One could lose US protection if one filed for the same patent in another country first, even as an afterthought in a different patent. It was a fine art to get the procedures exactly correct. #2909's belated use for protecting the phonograph was a lawyer's blunder, and Edison himself admitted it could never be "made right" because of the Dec 24th addition. I see little doubt as to the origins of Edison's phonograph, as arising directly from TAE's work with the telephone. Nor should one omit the contextual influence of the telegraph and its various 'repeaters.' Telephones were still quite expensive and could only be rented in 1877. One of Edison's anticipated uses for his recorder was to save messages intended for recipients who still did not own one - they could visit a central office and play back what they missed (for a fee) when the call came in. This must have seemed a good idea at the time, but it was also Edison's later insight that people would never sit in a darkened room with strangers to watch flickering lights. Patrick Feaster says: "We do not possess any document in which Edison explains the circumstances under which he thought his keyboard telephone might be used, or what its practical benefits might be." And yet also: "Edison's notebook entries of 26 May 1877 show that he was then already eager to build both a speech recorder and a speech generator," So I am confused. Is there a reason why this May 26th document was not quoted (in the article), regarding such a 'recorder'? And what was the actual imagined method of "recording"?. (Alllen Amet)There is a device at Greenfield Village in Michigan that is a pair of flat copper discs -- square -- on paired turntables. This is an Edison device which I believe Gelatt cited as an intermediary one on the way to the phonograph. It was designed to pick up telegraph signals and to etch them into the first copper disc. Then it would engrave the same signal to the second, which would send the second message out after a certain period of time. I assume the discs were removable, though they are screwed down with large brass bulbs. (David N. Davis)
Source : Feaster, Patrick (2007), "Speech Acoustics and the Keyboard Telephone: Rethinking Edison's Discovery of the Phonograph Principle," ARSC Journal 38:1 (Spring 2007), 10-43.
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