Audiology and Hearing Rehabilitation: Interpretation and Options
Core concepts
Know how to interpret pure-tone audiometry, speech audiometry, tympanometry, and acoustic reflexes, and how to select amplification. Distinguish conductive, sensorineural, and mixed hearing loss by air-bone gap. Understand speech reception threshold and word recognition score. Know cochlear implant candidacy: severe-to-profound sensorineural loss with limited benefit from hearing aids, and the role of the audiologist in mapping. Bone-anchored hearing aids suit conductive or single-sided deafness; conventional hearing aids suit sensorineural loss.
Traps in questions
- A word recognition score is a key determinant of cochlear implant candidacy, not just pure-tone thresholds.
- Bone-anchored devices bypass the middle ear and suit conductive loss or single-sided deafness.
- Type A tympanogram is normal; type B suggests effusion; type C suggests negative middle ear pressure.
- An air-bone gap indicates conductive or mixed loss, not pure sensorineural loss.
- Cochlear implants require an intact cochlear nerve; assess before surgery.
Worked rule of thumb
A patient with bilateral severe-to-profound sensorineural loss and poor word recognition despite appropriate hearing aids is a cochlear implant candidate. A patient with unilateral conductive loss and a normal cochlea is better served by a bone-anchored device.