An 83-year-old man has been convicted in the beating death of his 94-year-old roommate at a California health care facility, an attack prosecutors say was sparked by the older man's singing.

According to the Orange County Register, the district attorney's statement said William Leo McDougall pleaded guilty to second degree murder Friday in Superior Court.

McDougall and Manh Van Nguyen were both recovering from hip surgery at Palm Terrace Healthcare Center in Laguna Woods on Oct. 1, 2010.

Prosecutors say McDougall got mad because Nguyen was singing in Vietnamese, so he took a wooden rod from the closet and hit his roommate repeatedly in the head.

A nurse stopped the attack, but Nguyen later died due to blunt force trauma, the paper said.

McDougall now faces a tentative 16 years to life in state prison at his Oct. 26 sentencing, a term which will be suspended in lieu of lifetime probation.