He completed his residency in Otolaryngology at UBC in 1995, a one-year fellowship in Otology and Neurotology at the California Ear Institute at Stanford University in 1996, and his Master in Health Care and Epidemiology at UBC (now the School of Population and Public Health) in 1999. His clinical practice, since 1996, has been restricted to the subspecialty of otology and neurotology, which is the study of disorders of the ear and its related nervous system.

Dr. Westerberg has served the Royal College of Physicians and Surgeons as a Program Director for Otolaryngology – Head and Neck Surgery at UBC, as a member of the Examination Committee for his specialty, as Vice-chair and Chair of the Specialty Committee in OHNS, a member of the Residency Accreditation Committee and is currently a member of the International Residency Program Review and Accreditation Committee.

He has supervised numerous Masters and PhD candidates, and Clinical and Research Fellows. His interest in global surgery is apparent in his involvement in Zimbabwe and Uganda Hearing Health Care Programs, and local outreach within British Columbia. He is a Clinical Professor in the Department of Surgery and Medical Director of the Branch for International Surgical Care at the University of British Columbia.