Complete Audiological Evaluation
This is the initial evaluation which is done to determine if a hearing loss is present, and if so, to detail the type and severity of the hearing loss. Your hearing evaluation will begin with a thorough review of your medical history. Dr. Gordon or Dr. Lantz will ask questions about your hearing, and examine your ears with a lighted instrument known as an otoscope. This is to make sure there’s no earwax or a foreign object obstructing your eardrum. Finally, you’ll be given a series of hearing tests to determine whether you have a hearing loss and, if so, to what extent. It also may provide insight into the cause of the hearing loss as well as provide guidance for them in making appropriate treatment recommendations.
What Tests Will Be Done?
The specific tests done during the evaluation will depend on the patient's age, and what is known already about their hearing status. These various tests will determine the degree of hearing loss, the type of hearing loss, and the conditions of the ear canal and middle ear. The audiologist will also determine if the hearing loss is conductive (middle or outer ear problem) or sensorineural (inner ear problem or central processing difficulty of the brain).
Pure-tone Air and Bone Conduction Testing
Pure-tone air conduction testing determines the quietest tones that a person can hear at different selected pitches (frequencies), both low and high. Bone conduction testing is similar to pure-tone air conduction testing. Sometimes, use of earphones for the test is not possible, such as when a child refuses to wear them. In these cases, sounds are presented through speakers inside a sound booth (called sound-field screening). A different type of headphone is used during bone conduction testing, and the results help them determine if the hearing loss is originating from the outer/middle ear or from the inner ear.
Tympanometry provides a way, along with a physical exam, for Dr. Gordon & Dr. Lantz to diagnose and monitor problems in the middle ear. The middle ear is located behind the tympanic membrane (eardrum).Tympanometry can help diagnose disorders that can lead to hearing loss, especially in children. This test measures the movement of your tympanic membrane in response to changes in pressure. The tympanic membrane is a thin tissue that separates the middle and outer ear segments. The results of a tympanometry are recorded on a graph called a tympanogram.
The test determines if you have fluid in your middle ear, otitis media (middle ear infection), a perforation (tear) in the eardrum or a problem with the Eustachian tube (the tube that links the upper part of the throat and nose with the middle ear)
A speech reception threshold (SRT) test is often used with older children and adults to confirm the results of a pure-tone test. This test determines the lowest level at which the patient can recognize words or speech stimuli.
Specialized tests exist for infants and young children, as well as children and adults with developmental and cognitive impairments. These more-specialized tests allow us to test the auditory system when the patient is not able to actively participate in the tests or evaluation.
Otoacoustic emissions (OAE)
Otoacoustic emissions are sounds given off by the inner ear when the cochlea is stimulated by a sound. When sound stimulates the cochlea, the outer hair cells vibrate. The vibration produces a nearly inaudible sound that echoes back into the middle ear. The sound can be measured with a small probe inserted into the ear canal.
People with normal hearing produce emissions. Those with hearing loss greater than 25–30 decibels (dB) do not produce these very soft sounds. The OAE test is often part of a newborn hearing screening program. This test can detect blockage in the outer ear canal, as well as the presence of middle ear fluid and damage to the outer hair cells in the cochlea.
Visual reinforcement and conditioned play audiometry for children
Visual Reinforcement Audiometry (VRA) is a behavioral audiometric test obtained in a soundproof booth. This test is used to measure the hearing of children age 7 months to 2 1/2 years. The child is seated on a parent's lap or in a chair between two calibrated loudspeakers, or using earphones. When a sound is presented, the infant's eye-shift or head-turn response toward the sound source and is rewarded by activation of a lighted mechanical toy mounted near the loudspeaker.
Conditioned Play Audiometry is a behavioral test also obtained in a soundproof booth, and is used to test the hearing of children age 2 1/2 years to 5 years. Using positive reinforcement, Dr. Gordon or Dr. Lantz "trains" the child to place blocks or balls in a basket whenever he/she hears a tone.
During the test, they reduce the intensity of both the sound and the stimuli until the child's minimum hearing threshold is reached. Tests continue using different frequencies until they have a complete set of data about your child's hearing in both ears.
For children, it is important to have a diagnostic audiological evaluation whenever a hearing loss is suspected. It is the first step in identifying hearing loss and dealing with it to improve quality of life.