Types of Hearing Loss

Hearing loss can vary in degree, ranging from mild to profound and can also vary based on different pitches or frequencies. A hearing test can determine the extent of your hearing loss compared to an average of other adults with typical hearing.

The volume of sounds you can hear is measured in decibels (dB), with the softest whisper at 15-20 dB and a jet engine at 120 dB. The lowest sounds you can hear are called thresholds. Normal hearing thresholds for adults are between 0-25 dB across the frequency range tested. The evaluation also includes speech testing, which measures the level of particular words you can hear clearly. This helps to identify the type of hearing loss, which can be categorized as conductive, sensorineural or mixed.

Conductive Hearing Loss

When there is an issue with how sound is transmitted to the inner ear and the cochlea, it results in conductive hearing loss. This problem can arise in the ear canal, the eardrum (tympanic membrane), or the middle ear (ossicles and Eustachian tube). However, the inner ear and auditory nerve remain unaffected in this type of hearing loss.

Symptoms of conductive hearing loss are similar to those of other types, but individuals may report that sounds seem muffled or too faint.

Hearing Loss Causes

Some of the common causes of conductive hearing loss are outer or middle ear infections, complete earwax blockage, deterioration of the middle ear bones, otosclerosis, a perforated tympanic membrane, or the absence of the outer or middle ear structures. Depending on the source of the problem, conductive hearing loss may be temporary or permanent. Medical treatment can correct some cases of conductive hearing loss, while hearing instruments may be recommended for long-standing or permanent cases.

Sensorineural Hearing Loss

Sensorineural hearing loss is caused by a problem in the sensory receptors of the hearing system, which is usually located in the cochlea of the inner ear or auditory nerve. In most cases, this type of hearing loss is due to damage or abnormalities in the hair cells of the cochlea, which disrupts the transmission of sound to the brain. People with sensorineural hearing loss may experience difficulty hearing in noisy environments, problems with clarity of speech, tinnitus (ringing in the ears), and muffled speech.

Sensorineural Hearing Loss Causes

Sensorineural hearing loss can be caused by congenital conditions where hair cells in the inner ear are abnormal from birth, or due to damage caused by genetics, infection, drugs, trauma or over-exposure to noise. Another common cause of sensorineural hearing loss is presbycusis, which is age-related hearing loss.

This type of hearing loss is typically permanent and may worsen over time, requiring routine hearing tests to monitor changes. Hearing aids are often the most successful treatment option and can be adjusted by hearing professionals to meet changing needs.

Mixed Hearing Loss

Mixed hearing loss is a condition where a person has both sensorineural and conductive hearing loss. This implies that there is an issue in the inner ear as well as in the outer and/or middle ear.

The conductive hearing loss can be either temporary or permanent, depending on the cause of the problem. Medical management can sometimes treat mixed hearing loss, and hearing aids are commonly recommended as a treatment option.