Gena Krohmer, age 14, of Missoula, Mont., for her question:

WHAT IS AUDIOLOGY?

Audiology is a profession devoted to the diagnosis and treatment of hearing problems. An audiologist is a person who determines whether a patient has defective hearing and he also measures the effect of a partial or total hearing loss on the patient's ability to communicate.

An instrument called an audiometer is used by the audiologist to electronically measure hearing ability. If a hearing aid is needed, the audiologist fits him with one as part of the treatment.

To practice audiology in the United States, a person must have a certificate from the American Speech and Hearing Association. In some states, he also must pass an examination for a state license.

An audiologist must have at least a master's degree in audiology, but an increasing number have a Ph.D. degree as well.

Audiologists work in various speech and hearing centers, medical clinics, hospitals and schools. Some specialists have private practice.