Texas Occupations Code - OCC § 402.402. Sale to Minor

(a) A licensed hearing instrument fitter and dispenser may not sell a hearing instrument to a person under 18 years of age unless the prospective user or a parent or guardian of the prospective user has presented to the hearing instrument fitter and dispenser a written statement, signed by a licensed physician , that states that the patient's hearing loss has been medically evaluated and that the patient may be considered a candidate for a hearing instrument.  Whenever practicable, the medical evaluation should be performed by a licensed physician who specializes in diseases of the ear.

(b) The physician's evaluation must have taken place within the preceding six months.