Hugo Lieber (1868-1936) was a German chemist who moved to New York in 1891, became interested in hearing problems in 1922, established the Sonotone Corp. in 1930, and introduced the first Sonotone hearing aid in 1932. As Waldemar Kaemffert explained in the New York Times: “Instead of forcing intensified sound waves through the impaired ear by a modified telephone, thus distorting sound and imposing a strain on the deaf hearer, Dr. Lieber’s oscillator detours the sound around the outer ear directly to the internal hearing organs. Sounds so heard are not distorted. The device makes use of the principle that sound vibrations are conveyed with greater ease through certain solids, including human bones, than through the air.” The Sonotone Corp. donated this Model 531A hearing aid to the Smithsonian in 1944. An inscription reads "SONOTONE / U.S.PAT. 1.679.532 PAT. / PENDING. MADE IN U.S.A. / M33469." The referenced patent was issued to Frederick William Kranz (1887-1979), a physicist with a Ph.D. from the University of Chicago, who served for many years as a vice-president of Sonotone.
Ref: Walter Kaemffert, “This Week in Science,” New York Times (Nov. 6, 1932), p. XX4.
“Dr. Lieber is Dead; Device Aided Deaf,” New York Times (Jan. 4, 1936), p. 15.
Frederick William Kranz, “Apparatus for Aiding Hearing,” U.S. Patent 1,679,532 (Aug. 7, 1928).