Photographing the Human Voice by Radio

Photographing the Human Voice by Radio

A. Hyatt Verrill

The Photographic Journal of America, Apr 1, 1923; 60, 4; researched by Alan Schenker, digitized by Doug Frizzle May 2012.

How would you like to sit in a darkened room and see a moving picture of your voice thrown on the screen before you?

At first such a question sounds highly ridiculous, and you may say or think it's nonsense to talk about such an impossible feat. But modern radio has made many seemingly impossible things not only possible but simple, and among others it has made possible the actual photographing of the human voice and other sounds.

When we come to think of it, it is not so very remarkable either, for light rays, radio waves and sound waves are all vibrations of the ether: and while radio waves and light waves are inaudible and sound waves and radio waves are invisible, yet we know that sound waves can be made visible by means of certain arrangements of mirrors that reflect light rays varied by sound, and we know that radio waves may be made audible by the radio telephone and that light waves may be rendered audible by the selenium mirror as arranged by Professor Bell. So it is only a step to arranging delicate mechanism in such a way as to render the voice visible and then photograph it with a motion picture camera.

But it was not until the invention of the vacuum tube or audion bulb that radio telephony became really practicable, and the little tube—which is perhaps the most remarkable of man's inventions and the most delicate instrument ever devised—is what made it possible to reproduce the human voice and other sounds on a motion picture film.

The discovery of how to do this—and there are several methods—has opened up a wonderful field. First, there is the possibility of having talking pictures—motion pictures in which we see the various characters and also hear them talking, exactly as if we were really seeing and listening to them. Perhaps this may never be very popular, for many people prefer to imagine what the actors and actresses are saying. Then, again, it is very hard to find actors and actresses who can act before a camera and are also able to carry on a speaking part well. But there are many pictures where the new invention will be of the greatest value and will add immensely to the realism and enjoyment of the pictures. We will be able to hear the thunder of storms, to hear the boom of surf, the roar of cataracts, the rush and sweep of gales, the ringing of bells, the reports of guns and artillery, the clatter of horses' hoofs, the sounds of battle, the songs of birds, the barking of dogs, the music of bands, the notes of musical instruments, and the puffing and snorting of locomotives, not to mention the clanging of fire engine gongs and the screech of motor horns. All these will soon be as much a part of motion pictures as the titles and headings and all because of the vacuum tube.

And now, perhaps, you wonder how this seeming miracle can be accomplished. It is really very simple. In the motion picture camera is a small, brilliant light—or in one process a specially designed mirror—operated by electricity and connected with a vacuum tube in such a way that every variation of the current flowing through the tube increases or decreases the amount of light. That is, instead of the variation of the current through the tube causing vibrations on a diaphragm in a phone, so the currents reproduce sound, the variations in the tube cause the light or the mirror to fluctuate.

Then, connected with the tube, exactly as in a sending set, is a microphone and horn, which catch the voice or other sound. Thus, when the camera is taking the pictures and the person is talking, the little light flares up and down; and as the pictures are recorded on the film, a little wriggly, irregular line of light is cast on one edge of the film at the same time. Then, when it is wished to reproduce the sound, the positive printed from the film negative is run through another projection machine, with a small powerful light arranged so it will shine on the mark made by the light that was varied by the sounds. In the negative, of course, the mark made by the light was black, and in the positive, therefore, it will lie clear or transparent, so that the light falling upon it will shine through. Back of the strip of film is a mirror and a vacuum tube receiving set, which in turn is connected with an amplifier and a loud speaker. The beam of light striking through the transparent line on the film and hence on the mirror varies the flow of the electric current through the tube and thus causes a vibration in the ‘phone diaphragm which is magnified by the amplifying tubes and the loud speaker.

And not only does this invention open a new field for motion pictures. Perhaps it has even a greater value as a means of reproducing songs, music and other sounds on the phonograph. For in this way records may be made on strips of films, and then, by running the film through a special form of phonograph, the sounds will be reproduced without the least scratchy or buzzing noise, which is so troublesome with ordinary records. And there is still another use for this method of reproducing sounds which has already been tried out with the greatest success. This is in broadcasting music, songs, speeches, etc. by radio. Instead of having the performers talk or sing or play into a horn and a microphone, their voices or the music may be recorded at any time convenient on a strip of film and then broadcast whenever desired. Already some of the big stations have done this, and no one who listened in to the concerts and the entertainments realized that, instead of listening to the voices of the singers and the sounds of the orchestra, they were listening to sounds which had been made visible on a film.

And now we get back to my first question about seeing a motion picture of your voice. That is the simplest thing of all; for once the sounds are recorded on the film, it is only necessary to run the film through a projection machine, and we can see exactly how a song or a sentence or a speech or music or any other sound looks. Perhaps, some day, these zigzag lines recorded on films will take the place of writing; and instead of reading books and papers and magazines, and even letters, printed in type on paper, we will read wavy lines, the real words made visible without the clumsy, roundabout method of writing and spelling and printing. Who knows?