Leon Loeb, 75, who served as president of Sound Studios Inc., a recording firm in Washington, from 1948 until retiring in 1968, died Wednesday in Frederick Memorial Hospital. He had a heart ailment.

A resident of the Frederick area in Maryland since 1947, he had commuted to Washington after joining Sound Studios. He also had maintained an apartment in Washington from 1958 to 1968. In the early 1950s, he was general manager of the former FM radio station WCFM when some of the services and facilities of Sound Studios were consolidated with the station.

Mr. Loeb was born on Long Island, N.Y. He was a graduate of Dartmouth College, received a certificate from the Sorbonne in Paris and attended Harvard Law School. Before attending college, he had served at an early age in the Merchant Marine.

In the 1930s, he worked with artists and represented industrial designers in New York. He served in the Army in World War II.

Mr. Loeb was a member of the National Press Club and the National Democratic Club.

Survivors include his wife, Ethel, of Frederick; a brother, Albert, of Sylmar, Calif,; a stepdaughter, Mary Jeanne Carrera of Falls Church, and a stepson, Dr. William E. Adamson of Evansville, Ind.