California Code, Business and Professions Code - BPC § 2539.6

(a) Whenever any of the following conditions are found to exist either from observations by the licensed audiologist or on the basis of information furnished by the prospective hearing aid user, a licensed audiologist shall, prior to fitting or selling a hearing aid to any individual, suggest to that individual in writing that the individual's best interests would be served if they consult a licensed physician and surgeon specializing in diseases of the ear or, if none are available in the community, a duly licensed physician and surgeon:

(b) No referral for medical opinion need be made by any licensed audiologist in the instance of replacement only of a hearing aid that has been lost or damaged beyond repair within one year of the date of purchase. A copy of the written recommendation shall be retained by the licensed audiologist for the period provided for in Section 2539.10. A person receiving the written recommendation who elects to purchase a hearing aid shall sign a receipt for the same, and the receipt shall be kept with the other papers retained by the licensed audiologist for the period provided for in Section 2539.10. Nothing in this section required to be performed by a licensed audiologist shall mean that the licensed audiologist is engaged in the diagnosis of illness or the practice of medicine or any other activity prohibited by the provisions of this code.