During air conduction testing, tones are presented through headphones or small insert earphones to determine your threshold. A threshold is the softest tone one hears 50% of the time. This is done across the frequency range of 250-8000 Hz and results are plotted on an audiogram.
Bone conduction testing requires a small oscillator attached to a headband to be placed behind the ear. This testing bypasses the outer and middle ear, and assesses only the inner ear. By reviewing the results of the bone conduction testing, compared to the air conduction testing, the audiologist can determine if your hearing loss is a result of a problem in the outer, middle, and/or inner ear.
Speech Recognition and Identification
Speech Recognition testing is obtained using headphones or small foam insert earphones. The audiologist will ask you to repeat several two syllable words as the volume of their voice decreases. This is used to determine the softest level which you can successfully repeat back the words 50% of the time. Speech Identification scores are obtained in a similar fashion, as you will be asked to repeat back several one syllable words. However, for this test, the words are presented at a comfortable volume. This is a measure of how well you can identify spoken words in a quiet listening situation, without visual cues, at a volume you can easily hear.
Tympanometry
Tympanometry assesses your middle ear status. During this test, a small, soft probe tip is inserted into your ear. You will hear a tone and feel a momentary pressure change. Information obtained from this test can provide important information regarding the eardrum and middle ear cavity.
Accoustic Reflexes
This testing is often performed immediately following tympanometry. While the probe tip is still in your ear, you will hear several loud, brief tones at various frequencies. The acoustic reflex test looks for a contraction of a small muscle in the middle ear. This test can provide important information regarding your VII (facial) and VIII (hearing and balance) cranial nerves.
Testing Children
Image courtesy of Natus Medical Incorporated
0-6 months: Objective diagnostic testing that requires no response from the baby is performed to assess the structures responsible for hearing. Screening or diagnostic Otoacoustic Emissions and/or Auditory Brainstem Response testing is utilized for this population.
7 months: Children develop the ability to localize sounds, which enables assessment using speakers and toys. When the child correctly and appropriately identifies the direction of the sound, s/he is rewarded with seeing the toy.
6 months - 2½ years: Children can reflexively participate in behavioral audiometry. This type of evaluation usually involves the child sitting on an adult’s lap with speech and tonal sounds coming from speakers placed on both sides of a soundproof booth. These results may be obtained with or without headphones.
3 years +: Children can actively participate in behavioral audiometry. This type of evaluation usually involves the child sitting and playing ‘listening games’ with blocks or toys using speech and tonal sounds. These results are usually obtained with headphones.
Pure Tone Air and Bone Conduction Testing
