While a comprehensive audiological evaluation involves numerous tests, the three fundamental types of hearing tests are: pure-tone audiometry, speech audiometry (which includes speech discrimination tests), and, though not specifically a test, special testing for children.
Here's a more detailed breakdown:
-
Pure-Tone Audiometry:
- This is the foundational test. It determines the softest sounds a person can hear at different frequencies (pitches).
- An audiometer is used to present tones through headphones.
- The results are plotted on an audiogram, which visually represents hearing sensitivity.
- This test identifies the type and degree of hearing loss.
-
Speech Audiometry:
- This category includes various speech tests designed to assess how well a person understands spoken words.
- Speech Reception Threshold (SRT): Determines the softest level at which a person can repeat spondaic words (two-syllable words with equal stress, like "baseball" or "airplane").
- Speech Discrimination/Recognition Testing: Assesses how well a person can understand single-syllable words presented at a comfortable listening level. This helps determine the clarity of hearing and the ability to distinguish between similar sounds.
-
Hearing Tests for Babies and Children:
- Because babies and young children cannot respond to standard hearing tests, special testing methods are required. While not a single test, this is a grouping of techniques.
- Auditory Brainstem Response (ABR): Measures the electrical activity in the brainstem in response to sound.
- Otoacoustic Emissions (OAEs): Measures the sounds produced by the inner ear. A probe is placed in the ear and the response of the cochlea is recorded.
- Visual Reinforcement Audiometry (VRA): Used for older infants and young children; they are conditioned to turn their head towards a sound source that is paired with a visual reward (e.g., a lighted toy).
- Conditioned Play Audiometry (CPA): Children are taught to perform a play activity (e.g., dropping a block in a bucket) each time they hear a sound.
These three categories encompass the core methods used to evaluate hearing function across all ages.
