KembaraXtra – Psychology: Conductive Deafness

Definition

Conductive deafness, also called conductive hearing loss, conduction deafness, or transmission deafness, is hearing impairment caused by interference with the transmission of sound through the outer or middle ear. The inner ear and auditory nerve may remain relatively intact.

Auditory Mechanism

Sound waves normally travel through the ear canal, vibrate the tympanic membrane, and pass through the middle-ear ossicles to the cochlea. Blockage, inflammation, structural abnormality, or impaired movement of these structures reduces the amount of acoustic energy reaching the inner ear.

Causes and Characteristics

Common causes include impacted earwax, middle-ear infection, perforation of the tympanic membrane, fluid accumulation, and otosclerosis affecting movement of the stapes. Sounds may seem quieter or muffled, but speech clarity may improve substantially when volume is increased.

Clinical Assessment and Treatment

Assessment may include otoscopy, pure-tone audiometry, tympanometry, and bone-conduction testing. Treatment depends on the cause and may involve removal of obstruction, medication, surgery, or hearing devices. Conductive hearing loss must be distinguished from sensorineural loss, which arises from damage to the cochlea or auditory nerve.

Summary

Conductive deafness results from impaired transmission of sound through the outer or middle ear. Common causes include wax, infection, fluid, and ossicular abnormalities. It often reduces loudness more than clarity. Many forms are medically or surgically treatable.