Shearer was born in Westmount, Quebec, to a prominent family that fell on hard times after his father's business failed, which ultimately led to his parents' separation.

"[3] Douglas became a significant inventor and innovator in sound technology, with one of his many contributions being a system he developed that eliminated unwanted background noise.

Over his long career, Shearer was nominated twenty-one times for Academy Awards, winning seven Oscars for Sound and Special Effects.

In summing up his career, The Film Encyclopedia by Ephraim Katz (2001) states that "during his more than 40 years with MGM he contributed more than any other man in Hollywood to the perfection of motion picture sound.

In its October 4, 1932 issue, the trade paper The Film Daily announced that "Douglas Shearer, head of the M-G-M sound department...has returned [to Hollywood] from an 'aerial honeymoon' with his bride, formerly Ann Cunningham, also of the studio staff.