While “sensorineural hearing loss” is caused by inner-ear hair-cell damage or problems with nerve pathways that lead from the inner ear to the brain, “conductive hearing loss” is related to problems conducting sound waves from the outer ear to the middle ear. While sensorineural hearing loss accounts for about 90% of all hearing loss and may generally be treated with a hearing instrument, a conductive loss is largely a medical problem that can be treated with medication or surgery. In some cases, conductive hearing loss can be treated simply by removing impacted ear wax – a blockage to the transmission of sound waves. With this in mind, it is recommended that everyone forego the use of cotton swabs to “clean” their ears.
P.S. If left to its own devices, ear wax (cerumen) will migrate out of the ear canal, providing protection against bacteria as it goes.