Cal. Bus. & Prof. Code § 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:
1. (1) Visible congenital or traumatic deformity of the ear.
2. (2) History of, or active drainage from the ear within the previous 90 days.
3. (3) History of sudden or rapidly progressive hearing loss within the previous 90 days.
4. (4) Acute or chronic dizziness.
5. (5) Unilateral hearing loss of sudden or recent onset within the previous 90 days.
6. (6) Significant air-bone gap when generally acceptable standards have been established.
7. (7) Visible evidence of significant cerumen accumulation or a foreign body in the ear canal.
8. (8) Pain or discomfort in the ear.
(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.