Founded by L. Glen Pew in 1952, Electro Acoustic Company (EAC) began as a part-time business calibrating and repairing audiometers, primarily in the greater San Francisco Bay Area. By the mid-1960s, it became a full-time endeavor. In 1974, the company expanded to include all of Northern California, Nevada and Utah, and represented Beltone, Zenith, Tracoustics and other equipment lines.

On March 1, 2013, EAC was sold to what is now known as e3 Diagnostics.

Health Care Instruments (HCI) began in 1992 as MSR California (founded and operated by Roger Ott and Brian Hillabush). In 1999, Ron Macon (brother-in-law of Brian) and Merlyn Lubiens purchased MSR California from Roger and Brian, and changed its name to Health Care Instruments. In 2000, Ron Macon purchased Merlyn’s share of the company and assumed 100% ownership. Also in 2000, Dan Hatch joined the company as its CFO.

In the ensuing years, HCI specialized in higher-end equipment (ENG/VNG, Real Ear, OAE, and ABR) though it serviced and sold equipment to a full range of clientele – from screening to diagnostic to clinical. HCI excelled, in particular, as an exclusive manufacturer’s representative for Audioscan and Bio-logic. Ron Macon sold HCI to what is now known as e3 Diagnostics on January 31, 2013.

Duane Hillabush, began working in the field in 2007, first providing engineering and sound booth installations for MSR. At that time, his company was known as Sonic Acoustics. Duane even dabbled in building sound booths that he sold to MSR. Beginning in 2010, Duane provided booth installation and other services for Health Care Instruments. In 2010, Duane incorporated his business as Sonic Medical Devices. He began by distributing for Maico and Otodynamics, and later formed a relationship with Interacoustics. Duane sold Sonic Medical Devices to e3 Diagnostics on January 30, 2013.