An audiometry exam tests your ability to hear sounds. Sounds vary based on their loudness (intensity) and the speed of sound wave vibrations (tone).
Hearing occurs when sound waves stimulate the nerves of the inner ear. The sound then travels along nerve pathways to the brain.
Sound waves can travel to the inner ear through the ear canal, eardrum, and bones of the middle ear (air conduction). They can also pass through the bones around and behind the ear (bone conduction).
The INTENSITY of sound is measured in decibels (dB):
A whisper is about 20 dB
Loud music (some concerts) is around 80 – 120 dB
A jet engine is about 140 – 180 dB
Sounds greater than 85 dB can cause hearing loss after a few hours. Louder sounds can cause immediate pain, and hearing loss can develop in a very short time.
The TONE of sound is measured in cycles per second (cps) or Hertz:
Low bass tones range around 50 – 60 Hz
Shrill, high-pitched tones range around 10,000 Hz or higher
The normal range of human hearing is about 20 Hz – 20,000 Hz. Some animals can hear up to 50,000 Hz. Human speech is usually 500 – 3,000 Hz.
How The Test Is Performed
The first steps are to see whether you need an audiogram. The procedure most often involves blocking one ear at a time and checking your ability to hear whispers, spoken words, or the sound of a ticking watch.
- New Born Hearing ScreeningPaediatric1
- Complete Hearing Assessment
- Behavioral Observation Audiometry (BOA)
- Speech Audiometry
- Immittance Audiometry (Tympanometry & Acoustic Reflexes)
- Otoacoustic Emission Testing (OAE)
- Auditory Brainstem Response Testing (ABR)
- Automated Steady State Response Testing (ASSR)
- Trans Tympanic Electric Auditory Brainstem Response Testing (TTEABR)
- Aided Audiometry
Auditory Verbal Training
Rehabilitation is an essential part for those who have undergone Cochlear Implantation. All patients need Auditory Verbal Therapy (AVT). In Auditory Verbal Therapy, the emphasis is laid on making the child listen and speak normally, rather than on lip reading and visual cues. Learning to listen takes time and requires concerted efforts from the patient, the family and the person providing habilitation services. Thus the implant can offer a wide range of benefits, including hearing speech, environmental sounds and music.
Auditory Brainstem Implant
An Auditory Brainstem Implant (ABI) is a modified cochlear implant intended to be used to stimulate the cochlear nucleus in the brainstem of patients who have had their eighth
nerves severed during surgery for removal of bilateral neurofibromata, as in patients with Neurofibromatosis 2 (NF2).
The cochlear implant linear array of electrode contacts is replaced by a small rectangular silastic paddle containing the 21 contacts. This is surgically inserted into the lateral recess of the fourth ventricle. The need for this device is much less common than that for a cochlear implant, but these patients are typically totally deaf and, although the benefit is
not as great on the average as that of the cochlear implant, most recipients derive significant auditory perception.