Exhibit Curated and Digitized by Christian Crouch

How Sound Is Stored Physically

Physical audio storage varies a little from device to device, but there are two main types that you will find - lateral cut and vertical cut. Of the devices in this exhibit, the Dictaphone phonographs use the vertical cut method, while the Victrola gramophone uses the lateral cut method. The essence of the two recording methods are the same, however the lateral cut method creates and reproduces sound by vibrating the needle to the left and right. This horizontal vibrating motion creates a path that is similar to a river, flowing back and forth in the shape of the recorded sound. The vertical cut method, sometimes known as “hill and dale,” records and reproduces by plunging the needle either deeper or shallower depending on the sound frequency, creating the hills and dales the method is known for. While both methods are equally viable and saw significant usage, the vertical cut method faded to obscurity in favor of the lateral cut method due to the increased cost and complexity, requiring a few extra pieces on the play-head.

Before the widespread use of electricity throughout the United States, recording was done through physical means by the use of sound waves. All sound is composed of vibrations of various frequencies that vibrate the air molecules around us. These vibrations eventually hit our eardrums in such a way that our brain can understand and decode what we know as sound. In a similar way to the inner ear and eardrum, the forms of recording that are here before you utilize a speaking tube (like the handheld one found on the Ediphone Model 12) that captures the vibrations that enter into it and funnel it to a piece called a diaphragm (shown on the photo above). These diaphragms were made of many different types of material and each had their own benefits and deficits. For instance, glass and mica diaphragms were sometimes used on different Dictaphone phonograph models. Glass is a more rigid material which doesn’t vibrate nearly as much as mica, this often meant that glass was much better at capturing very loud sounds versus very quiet sounds. The opposite was generally true of the mica, which excelled at quiet sounds, but became distorted at high volumes. The diaphragms were connected through a small piece of metal to the stylus which would vibrate and “write” the sound into the wax cylinders or records beneath.

A very early recording of sound can be found below, released by the Smithsonian and reported by NPR- a short message from Alexander Graham Bell.

Dictaphone Model 12, Model 10, and Edison Shaving Machine

The Dictaphone Model 12 and the portable Dictaphone Model 10 are both examples of early 1920s dictation and transcription technology used by many offices and businesses around the United States. The Dictaphone brand originated with Alexander Graham Bell and Charles Sumner Tainter who established the American Graphophone Company in 1886. After merging with the Columbia Phonograph Company in 1889, the company transitioned from marketing to personal household usage into office dictation and transcription. This shift towards office dictation helped keep the business operating until their eventual shift away from the wax cylinder medium by 1950. Today, the renamed Dictaphone Corporation specializes in digital voice transcription and voice recognition technology under Nuance Communications. 

The Dictaphone has many of the same components as other devices of its time, namely a stylus connected to a glass, mica, or aluminum diaphragm, which then transmits sound through a connected amplifying horn. The Model 10 (A) is only used for audio playback; it cannot record audio of any kind. The Model 12 (B) can be used for both audio recording and playback due to the dual stylus layout of the machine. On the other hand, the Edison shaving machine (C) can neither record nor playback, instead it was used to “erase” the most recently recorded audio to allow for additional recordings on one single cylinder. The knob on the front of the machine would be operated to gently shave off a thin layer of wax using a sapphire cutting head. With efficient use of the shaver, it was reported that companies could expect around 100 individual recordings on each cylinder. A unique feature of these machines are the electric motors that would turn the cylinder lathe at a standard speed. Operated with a foot pedal instead of a hand crank, these machines would allow a secretary to transcribe efficiently with an accompanying typewriter.

Victor Talking Machine Co. “Victrola” Gramophone, 1906

This “Victrola” gramophone was created in 1906 by the Victor Talking Machine Company, based in Camden, New Jersey. The Victor Talking Machine Company was founded in 1901 by Eldridge Johnson, who was a previous business partner of Emile Berliner, the creator of the flat record disc. Johnson’s company was one of many that emerged at the time and survived until 1929, when they were purchased by the Radio Corporation of America (RCA) and merged into the RCA Victor company. This merger was closely related to the rise and popularity of radios in the home.

The gramophone you see here is a completely analog machine - using and requiring no electricity to function or reproduce sound. The handle on the right-hand side winds a spring motor that rotates the turntable at a standard speed indicated and changed by a knob nearby the tonearm. The tonearm and stylus are the pieces that create and transmit the sound from the stylus, through the tonearm, and down underneath the machine to be played from the internal horn. This particular device is an early version of the internal horn gramophones, and was superseded in 1925 by the much improved orthophonic gramophones produced by Victor Talking Machines in association with Western Electric. The internal horn on this machine simply directs the sound from the reproducer in the tonearm outward toward the listening audience. The orthophonic gramophones had folded internal horns that would increase volume and listening quality by creating a more balanced space for the vibrations to travel through the tonearm out to the listener. Volume could be changed on this machine by opening and closing the front panels to different degrees - fully open doors provided maximum volume, and fully shut doors provided minimum volume.

Timeline of Sound Reproduction

How sound is stored magnetically

Similarly to physical storage of sound on a record or wax cylinder, magnetic sound storage followed many of the same principles. In fact, magnetic recording and playback was invented less than a year after the Edison phonograph by Oberlin Smith and was officially patented 11 years later in 1889 by Valdemar Poulsen! The original magnetic recording devices created by Poulsen, called Telegraphones, looked very similar to phonographs, adopting the same cylinder shape as Edison. Different from Edison’s, these machines featured a thin piece of metal wire wrapped many times around the cylinder and oriented vertically instead of horizontally. 

Magnetic audio did not gain widespread popularity in the United States until nearly the end of World War II when Army Signal Corps Major John T. (Jack) Mullin sent back magnetophon tape players to the United States from Germany. Already somewhat common in Germany, the magnetophons acquired by Mullins featured improvements to the machine including high-frequency bias and PVC backed tape which greatly improved the quality of recording and playback. Mullins eventually created his own version of the magnetophon with the help of Ampex and debuted it by recording Bing Crosby in his radio show. Crosby personally placed an order for $50,000 worth of machines from Ampex which set in motion a radical change for the broadcast industry and eventually all audio reproduction. In fact, the adoption of magnetic tape also paved the way for computers with the UNIVAC computer in 1951 using magnetic tape as its storage medium.

Most magnetic players and recorders have a few components to read and write to magnetic tape. First, the tape runs across the erase head which, if powered, will erase anything already on a tape. Second, the tape will flow between a number of small electromagnets that create a tiny magnetic field. The number of magnets will change depending on the number of tracks the audio has, but they will function the same. These small magnets create magnetic fields that will “write” on the tape by aligning the small metallic particles into something similar to a fingerprint for the audio being recorded. If you then playback the tape, the playback head will do the same as the recording head, just in reverse. It will read the fingerprint for the audio and translate it back into a form that can be played through speakers.