Sierra Sound Laboratories

Recording and mastering studio in Berkeley near San Francisco, California (USA), founded in either 1959 or 1961 by Bob DeSousa. It consisted of two studios with a shared controlled room and was originally equipped with 4- and 8-track Scully recorders, with 8- and 16-track added later. It remained in operation into the mid-'80s, and by that time was comprised of one 16-track studio but without mastering services.

Studio manager: Harry Sobol (until 1970), Bob DeSousa (after 1970) .
Engineers: Peter Seplow (chief until 1970), Dennis Reed (mixer), Roy Ward (3), Lucy Sherak, Jimmy Nielsen.

Discs cut at the studio can be recognized by SSL etched in the runouts with the L extended below the S (sometimes read as SLS).

Also appears on releases as:
- Sierra Sound
- Sierra Sound Studio
- Sierra Sound Studios
- Sierra Sound Labs, Inc.