The Case Research Lab (CRL) was a private scientific research company founded by Theodore Case in Auburn, NY, United States. Case hired Earl I. Sponable in 1916, and the two men worked closely together for the next ten years. Together, they conducted work for the US Navy during World War I, and through this research developed a highly responsive photoelectric vacuum cell that CRL marketed as the “Thalofide Cell”. 

CRL began working in the developing field of sound recording, through the lab’s affiliation with Lee DeForest and his Phonofilm optical-sound project. In 1922, CRL began supplying Thalofide Cells for use in the sound reproduction of Phonofilm recordings and engaged in regular consultations with DeForest. At the time, DeForest was using commercially available flashlight bulbs to create Phonofilm, a system of variable-density soundtrack, exposed onto the same negative as the image. Variable electrical signals from a microphone were used to correspondingly vary the intensity of an exposing light source. The density of the exposed film stripe varied in proportion to the intensity of this lamp, creating graded striations, from light to dark. CRL made a critical breakthrough in December 1922, when Case developed a helium-filled gas discharge tube that could modulate more rapidly, and through a greater range of intensity, than the bulbs thus far used by DeForest. CRL’s glow lamp design, known as an Aeo light, resulted in sound negatives superior to those produced using DeForest’s method.

February 1923 should be seen as the start date of CRL optical sound recordings in earnest. A new “camera” (a modified projector) was refined over the winter of 1923. This gave CRL the ability to record and reproduce longer optical sound films within a research laboratory setting. Surviving CRL notebooks record a methodical, scientific approach to the problem, with variables being adjusted and results documented. Through 1923 and 1924, CRL developed an ever-stronger understanding of the principles of optical sound recording, which, from this stage on, became the primary focus of the lab’s activity. 

CRL’s methodical approach to addressing the existing shortcomings identified in optical sound recordings, contrasted dramatically with DeForest’s. In spring 1923, DeForest presented Phonofilm to the public, first through a press event in March, and then a larger public demonstration, in April at the Rivoli Theatre in Manhattan, New York – this, despite Case believing Phonofilm needed more refinement before going fully public. Throughout 1923, CRL notebooks and correspondence document Case’s growing frustration with DeForest and his penchant for showmanship over science and engineering. On several occasions, Sponable, Case and other CRL staff visited Phonofilm operations in New York to troubleshoot Phonofilm’s studio equipment. In early August 1924, Case, Sponable and others traveled to Washington, DC, to film US President Calvin Coolidge on the White House grounds, and Senator Robert LaFollette at the Capitol Building. While the recordings were arranged by Phonofilm staff, all the equipment used, as well as its operators, were provided by CRL. DeForest failed to duly credit CRL when these historic films were subsequently exhibited (Przyblek, 1999: p. 71).

Frustrated with the poor state of engineering at Phonofilm studio, with Phonofilm’s early theater installations and distribution practices, and leery of DeForest’s intentions to claim CRL innovations as his own, Case determined to develop a complete system for optical sound at his lab in Auburn without the involvement of DeForest. Although Case began to distance his lab from DeForest, contractual arrangements kept the two men linked through the remainder of 1924 (Przyblek, 1999: p. 74).

In August 1924, Case began construction work on a purpose-built studio in the attic of the carriage house on his Auburn estate. Once completed, the carriage house studio became the center of CRL’s filmmaking activities. Over 150 sound shorts had been filmed at CRL by the end of November 1926 (CRL Lab Notebook No. 1: “Studio Sound Tests”). These featured local musicians as well as vaudeville acts traveling through the area. Surviving films from this period are preserved at the George Eastman Museum in Rochester, NY. Preserved CRL Lab Notebook No. 12 includes positive frames cut from various films shot during 1925.

Throughout 1925, CRL focused its energy on perfecting its system and assessing potential strategies for the commercial exploitation of their technologies. With experience of making test films in the carriage house studio, CRL initially explored the idea of recording and distributing films as the path to commercialization. To do this it needed a license for the use of proprietary amplification technology, from either General Electric, or Western Electric. CRL’s attempt to secure such a license through the winter of 1925/26 proved unsuccessful (Sponable, 1947: pp. 296–301), but Case proceeded to incorporate the Zoephone Company as the prospective brand for films to be produced and distributed by CRL. 

Unable to secure an amplification license for himself, Case decided to partner up with an established film company to bring CRL sound to audiences. In July 1926, Case went into business with William Fox through the formation of the Fox-Case Corporation. Fox-Case Corp. signed a license with Western Electric for amplification on December 31, 1926, and premiered its first films in February 1927. These two contracts effectively brought an end to CRL sound as an entity, with their groundbreaking technologies subsequently becoming known as Fox Movietone.