About Hearing Loss
If you experienced a sudden hearing loss, please contact your medical provider immediately.
Hearing loss is described by varying degrees of severity (such as mild, moderate, moderately-severe, severe, or profound) and type (conductive, sensorineural, or mixed). Additionally, the severity and type may vary depending on pitches or frequencies (high, mid, or low pitches) range. A series of hearing tests can determine the amount of loss you experience.
The volume of sounds you hear is measured in decibels (dB). For example, 15-20 dB is equivalent to a soft whisper and 120 dB being a jet engine. The softest sounds you can hear are called thresholds and are determined by pure-tone testing. Normal hearing thresholds for adults are considered 0-25 dB across the range of frequencies tested. Speech testing is also conducted as a part of this series of evaluations and helps to assess the levels of particular words you can hear clearly.
Conductive hearing loss
Conductive hearing loss occurs when there is a problem with the way sound is conducted to the inner ear or cochlea. The problem may lie in the outer ear (pinna or ear canal), eardrum (tympanic membrane) or the middle ear (ossicles and Eustachian tube). The inner ear and auditory nerve remain unaffected in this type of hearing loss.
Some causes of conductive hearing loss can include outer or middle ear infections, complete earwax blockage, deterioration of the middle ear bones (ossicles), fixation of the ossicles (otosclerosis), a hole in the tympanic membrane, or absence of the outer ear or middle ear structures.
Conductive hearing losses may be temporary or permanent, depending on the source of the problem. Medical management can correct some cases of conductive hearing loss, while amplification (hearing aids) may be a recommended treatment option in more long-standing or permanent cases.
Individuals with conductive hearing loss may report that sounds are muffled or quiet. Generally, when sounds are made louder, these individuals can hear well again.
Sensorineural hearing loss
Sensorineural hearing loss occurs when there is a problem with the sensory receptors of the hearing system, specifically in the cochlea or auditory nerve of the inner ear. The majority of sensorineural hearing loss occurs as a result of an abnormality or damage to the hair cells in the cochlea. This abnormality prevents sound from being transmitted to the brain normally, resulting in a hearing loss.
The hair cells may have been abnormal since birth (congenital), damaged as a result of genetics, infection, drugs, trauma, or (sudden or over a period of time) over-exposure to loud sounds, or more commonly, damaged as a result of the aging process (also known as presbycusis).
Sensorineural hearing losses are generally permanent and some remain stable over time while others worsen. Therefore, routine hearing tests are needed to monitor the hearing loss. Treatment options, including hearing aids or cochlear implants in the most severe cases, are common recommendations.
Individuals with sensorineural hearing loss may report muffled speech, ringing in the ears (tinnitus), or difficulty hearing in background noise.
Mixed hearing loss
Mixed hearing loss occurs when a person has both sensorineural and conductive hearing loss components. It is, very literally, a mix of sensorineural and conductive hearing losses. This means there is a problem in the inner ear as well as in the outer or middle ear. The conductive hearing loss may be temporary or permanent, depending on the source of the problem.
Mixed hearing loss can sometimes be treated with medical management, and hearing aids are a common treatment recommendation.