Hearing Tests for Adults at Camino ENT
The Diagnostic Audiology Program at Camino ENT offers comprehensive audiologic evaluation and management of hearing impairment in children and adults.
Pure Tone Audiometry
Pure Tone Audiometry is a behavioral test used to determine hearing sensitivity. The patient is seated in a sound-treated room. Foam inserts or headphones are placed and the patient is asked to press a buzzer each time a sound is heard. The softest sound the patient can hear, called a threshold, is plotted on a graph called an audiogram. Thresholds are recorded for low (250 Hz) to high (8000 Hz) frequencies (pitch), for each ear individually. The audiogram shows whether the patient has hearing loss and to what degree.
If a hearing loss is diagnosed, it’s important to determine whether the loss is caused by a medical condition in the outer or middle ear that may be medically or surgically treatable. This type of hearing loss is called conductive. If the loss is caused by damage in the inner ear, the hearing loss is most likely permanent. This type of permanent hearing loss is called sensorineural. This distinction is made using a bone oscillator, which sends vibratory signals directly to the inner ear, bypassing the outer parts of the ear.
If hearing thresholds are better with bone conduction than through air conduction (inserts or headphones), this suggests a conductive hearing loss. When bone conduction thresholds are approximately equal to air conduction thresholds, this suggests a sensorineural hearing loss. A hearing loss with both sensorineural and conductive components is called a mixed hearing loss.
Once hearing thresholds are recorded for each ear, the audiologist can graph these results on a Familiar Sounds Audiogram, a similar graph to the audiogram. The Familiar Sounds Audiogram shows the loudness and frequency range of different environmental and speech sounds. It is easier to see, based on the hearing loss configuration, which sounds the patient has access to and which sounds the patient is “missing”.
Speech Audiometry is a measurement of speech reception and discrimination abilities. The patient is already seated for the pure tone audiometry portion of the hearing test. Through the inserted earphones or headphones, the patient will hear words descending in loudness and is asked to repeat each word or take a guess if the word is hard to recognize. The lowest level at which the patient can repeat the correct word two out of three times is called a speech recognition threshold. This threshold is recorded for each ear individually.
Once the speech recognition threshold is recorded for each ear, the audiologist will present a list of recorded words at a louder presentation level, depending on the patient’s degree of hearing loss, configuration and sensitivity to loud sounds. The patient is asked to repeat back each word, taking a guess even if the word is hard to understand. This test is more difficult, as it assesses the patient’s ability to understand single-syllable words with no contextual or visual cues.
Tympanometry is an objective test used to measure middle ear function. The patient is seated and a small rubber tip is placed at the entrance of the ear canal. The patient may hear a low buzzing sound and feel a change in pressure. If a tight ear seal can be obtained, the tympanogram will give the audiologist information about the volume of the ear canal, the resting pressure of the eardrum and the stiffness (or compliance) of the eardrum.
Tympanometry is helpful in determining whether the eardrum is moving sufficiently. If there is fluid behind the eardrum, Eustachian Tube dysfunction or a disarticulated ossicular chain (damage to the middle ear bones), the tympanogram may show an abnormal result. If the patient has a pressure equalization tube (PE tube), a tympanogram will show if the tube is open or clogged.
Acoustic Reflex Testing
Acoustic Reflex Testing is an objective test used to measure a reflexive response to intense sound in the middle ear. This test is usually completed at the same time the tympanogram is measured, as long as a good ear seal can be obtained. The patient is asked to sit quietly. Loud sounds are delivered to the ear canal and the reflex is observed. The threshold of the observed reflex is recorded for different frequencies (pitch).
This result is useful in checking consistency of hearing test results, especially in situations where the reliability of patient responses is questionable. This test can also provide insight into patients with central nervous system dysfunction.
Otoacoustic Emissions Evaluation
Otoacoustic Emissions Evaluation is an objective test used to measure inner ear hair cell function. There are two types of otoacoustic emissions used clinically. Transient-Evoked otoacoustic emissions (TEOAE) and Distortion-Product otoacoustic emissions (DPOAE) are used to verify results of the hearing test. The patient is seated and asked to remain very quiet and still. A series of sounds are presented to the ear through a small probe that fits inside the ear canal. The probe contains a tiny loudspeaker that generates the sounds and a microphone picks up an “echo” that is produced by the inner ear in response to those sounds.
Otoacoustic emissions, coupled with tympanometry, can be useful in evaluating whether the ear is clear and functioning for infants and young children. Even if behavioral measurements are unable to be obtained, these tests can give the audiologist and physician a good indication of whether the child has the ability to hear.
Hearing-in-Noise Testing is a recorded speech discrimination test that determines sentence speech reception thresholds in quiet or in noise. The patient is seated in a sound treated room and headphones are placed over the ears. The patient is asked to repeat back sentences heard through the headphones, in quiet and in noise. The HINT test is scored as a “pass” or “fail” result in each of four conditions. Results of the HINT test help indicate how the patient may be able to understand speech in noisy environments.
This test can be helpful for hearing aid users in determining whether a new hearing device benefits them in the presence of background noise. The HINT test is also a requirement for California Peace Officers who have hearing loss, to determine whether certain job duties are affected by the impairment.
High Frequency Audiometry
High Frequency Audiometry is a behavioral test used to determine hearing sensitivity for thresholds 8000 Hz to 20,000 Hz. The patient is seated in a sound treated room and headphones are placed over the ears. The patient is asked to press a buzzer to indicate when a sound is heard. Sounds are delivered to the ear and thresholds are recorded in the same way as standard pure-tone audiometry testing.
For patients taking ototoxic drugs, side effects can include hearing loss, tinnitus (“ringing” in the ear) and dizziness. High-frequency baseline thresholds can be measured prior to beginning ototoxic drug treatment, which can be potentially damaging to the ear. During the course of treatment, thresholds are monitored in order to inform the treating physician of any changes in hearing. Should the patient’s hearing deteriorate, the dosage may be altered or a different drug used to minimize hearing loss effects.