test battery breakdown
At The Hearing Room, we use an extensive battery of tests to ensure we accurately measure our patients’ hearing thresholds. The tests combined will provide the audiologist an understanding of the softest sounds audible at various frequencies, and will allow the clinician to define where in the auditory system the hearing deficit occurs.
A pure-tone air conduction test allows the audiologist to determine the softest sound an individual can hear across different frequencies. Frequencies tested in a typical air conduction assessment are 250hz to 8000hz. The patient being assessed wears insert earphones, or headphones, and is asked to identify each time they hear the tone, even if it is extremely faint. The method in conducting the test follows a psychometric function which yields near perfect accuracy within 5dB of the threshold (Ref. 1).
This test is similar to an air conduction test as described above, but is measured through a bone oscillator, which looks like a metal headband. This test bypasses the outer and middle ear, and specifically examines inner ear function. The combination of air conduction and bone conduction pure tone thresholds allow the audiologist to classify the type and degree of hearing loss. The method in conducting the test follows a psychometric function, which yields near perfect accuracy within 5dB of the threshold (Ref. 1).
Masking is conducted if there is expected hearing crossover from an ear with lower audiometric thresholds. White noise is played into the ear with lower audiometric thresholds to ensure an accurate measurement of the poorer ear is being recorded. Masking is used in both air and bone conduction tests.
A graph of the softest sounds audible at various frequencies using air conduction and bone conduction results. Measurements of loudness discomfort levels or uncomfortable loudness levels can also be measured if necessary.
This measurement is specific to testing how sound is transmitted through the middle ear space. It can help identify perforations to the tympanic membrane, otosclerosis, ossicle disarticulation, complete blockage of the outer ear by cerumen, or a flaccid tympanic membrane.
Speech testing can help validate the audiogram and allows the clinician to evaluate the volume level at which the patient is able to comfortably repeat words, and how well a patient is able to discriminate or understand words. While a word recognition test can allow the practitioner to have an understanding of the integrity of the auditory nerve, it does not predict a patients’ outcome with hearing aids (Ref. 2).
Visual Reinforcement Audiometry (VRA)
The Hearing Room performs pediatric assessments for children 2 and up. For children who are too young to verbally identify when they hear a sound, a testing procedure called visual reinforcement audiometry is employed. Sounds are presented in the sound booth through speakers. Insert earphones are preferred and used if the child can tolerate them. When a sound is presented, the child is conditioned to turn to a lighted toy or animal. Once the child is positively conditioned, the testing begins and thresholds can be determined.
Otoacoustic Emissions (OAE)
OAE’s are an objective test to help determine if there is hearing present. OAE’s are sounds emitted by hair cells when specific tones stimulate the inner ear. Hearing losses greater than 30 dB HL do not emit OAE’s as well as ears with middle ear dysfunction.
If you have more questions about hearing assessments or the audiometric test battery, feel free to call or email The Hearing Room. We have two hearing clinics located in Oshawa and one hearing clinic located in Stouffville to help serve you better. We hope to hear from you soon!