Bieri Hearing Specialists has continued to build on its unequaled reputation for providing the highest degree of patient satisfaction in the Mid-Michigan area. To accomplish this goal, we provide our patients with the area's largest selection of high tech hearing instruments. Rsquo; commitment to utilizing state of the art equipment to provide:. Bull; Hearing Aid Evaluations. Bull; Sound Field Testing. Bull; Speech Audiometry. Bull; Video Otoscopy. Bull; Cochlear Implant Screening. Bull; Speech Mapping.