Tympanometer

A tympanometer helps to diagnose middle-ear disorders, which can indicate a type of dysfunction in the Eustachian tube. The device changes the air pressure in the ear and makes it move the eardrum both back and forth, and can help diagnose tumors in the middle ear, perforated eardrums, impacted wax and other middle-ear disorders.

I recommend: Medline Plus has detailed information on the process of tympanometry and indications for usage, as well as possible disorders of the middle ear and other testing that can aid in diagnosis.

Audiometer

Audiometers test how well the ear is functioning and how well the nerve relays information to the brain.

I recommend: For an overview of audiometers, Medical Discoveries has an easy-to-read summary on the subject.

Bone-conduction test

Bone-conduction tests assess how soft a sound a person can hear over several pitches and frequency and can determine the extent to which there is a neurosensory hearing loss.

I recommend: The Medical College of Wisconsin Hearing and Balance Center has details regarding the process and procedure for bone-conduction tests. 

Pure-tone audiometry

Pure-tone audiometry testing assesses the amount of noise sensitivity transmitted through the outer, middle, and inner ear and then brain. This is done using headphones, which are placed over the ears to reduce ambient noise.

I recommend: American Speech-Language-Hearing Association has complete information concerning this type of testing, as well as other important information regarding hearing examinations.

Auditory brainstem response

Auditory brainstem-response testing is done to screen for deafness and hearing loss in newborn children. It is used as a method to help assess ear function, cranial nerve function and other types of specified brain functions within the lower aspect of the auditory system.

I recommend: Web MD has further information on this subject. 

Audiogram

An audiogram is done to show hearing capacity via a graphic representation and indicates the minimum intensity of sound that a person's ear can detect. It also evaluates the loudness of sound needed for hearing the tones in the musical scale. This chart or graph is the result of the hearing test conducted with audiographic equipment.

I recommend: The BC Children's Hospital has additional information on audiograms.