Air Conduction Testing:
Our audiologists test for the quietest beep the patient can hear at individual frequencies. We are finding the patients’ pure tone threshold. This is performed on adults and children using headphones or insert earphones. The adult or child is instructed to raise their hand every time they hear a beep. The frequencies most commonly tested are 250, 500, 1000, 2000, 4000, and 8000 Hz.
How do we hear the beeps when testing for air conduction thresholds?
The beep travels through the ear canal and vibrates the ear drum. The ear drum then vibrates three small bones in the middle ear. The three small bones, or ossicles, then vibrate the cochlea which organizes the information and sends it to our brain.
Bone Conduction Testing:
Bone conduction thresholds are commonly tested at 500, 1000, 2000, and 4000 Hz. Bone conduction testing is used to verify the type of hearing loss an individual has. This is performed on adults and children using a headband with a little box or vibrator that sits on the mastoid bone behind the ear. If the bone conduction thresholds are the same as the patient’s air conduction threshold then this indicates a sensorineural hearing loss. If the individual can hear the bone conduction beeps significantly better than the air conduction thresholds this indicates a conductive hearing loss.
How do we hear the beeps when testing for bone conduction thresholds?
The beep vibrates the box that is located on your mastoid (bone behind your ear). When the box vibrates it also vibrates the cochlea. Therefore, the sound vibrates only the cochlea and bypasses the middle ear bones (ossicles). It only vibrates the cochlea, which organizes the information and sends it to our brain.
Speech audiometry has evolved and is now significantly more detailed. It used to be simply repeating a list of words was all that was needed to determine how well a person can understand and process the speech signal. Now there are more advanced assessment tools available to assess how the auditory path performs. Many of these tools challenge the patient’s auditory processing system (the pathway of the hearing nerve to the auditory region of the brain).
Our comprehensive hearing evaluation includes an evaluation of speech processing capabilities in both quiet and in noise. This assessment helps determine the kind of hearing assistance a patient requires.