The state of California Speech Pathology and Audiology Licensing Board Department of Health Services offers a Certificate of Registration to work as an  Audiology Assistant or Aide in medical clinics, audiology private practices, and in the public schools. This certificate enables the holder to perform hearing conservation audiology and hearing aid services under the supervision of a registered Audiologist, which include: hearing screening, hearing threshold testing, tympanometric testing, referral,; assisting with pediatric testing and other special testing such as ABR, ENG, and VNG; set up, troubleshoot, clean, evaluate and service hearing devices, and take earmold impressions. Application for state registration requires that a licensed audiologist submit the application on behalf of the audiology assistant to verify supervision during employment.