California Code, Business and Professions Code - BPC § 2538.36

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

(b) No referral for medical opinion need be made by any licensee 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 licensee for the period provided for in Section 2538.38. A person receiving the written recommendation who elects to purchase a hearing aid shall sign a receipt, and the receipt shall be kept with other documents retained by the licensee for the period provided for in Section 2538.38. Nothing in this section required to be performed by a licensee shall mean that the licensee is engaged in the diagnosis of illness or the practice of medicine or any other activity prohibited by the provisions of this code.