From the Guidelines
Sensorineural hearing loss is a type of hearing loss that occurs due to damage to the inner ear (cochlea) or to the nerve pathways from the inner ear to the brain, resulting from abnormal function of the cochlea, auditory nerve, or higher aspects of central auditory perception or processing. This condition affects the transmission of sound signals from the inner ear to the brain, rather than problems with sound waves reaching the inner ear as seen in conductive hearing loss 1. Sensorineural hearing loss is typically permanent and can be caused by various factors, including aging, exposure to loud noise, certain medications, genetic factors, head trauma, or infections like meningitis.
Key Characteristics of Sensorineural Hearing Loss
- It is typically permanent and cannot usually be corrected with surgery or medication
- Management typically involves hearing aids, cochlear implants for severe cases, or assistive listening devices
- People with this type of hearing loss often have difficulty understanding speech, especially in noisy environments, and may experience tinnitus (ringing in the ears) as well
- The most frequently used audiometric criterion for sudden sensorineural hearing loss is a decrease in hearing of 30 decibels affecting at least 3 consecutive frequencies 1
Diagnosis and Management
The diagnosis of sensorineural hearing loss involves distinguishing it from conductive hearing loss, which can be done through physical examination and tuning fork testing 1. The management of sensorineural hearing loss focuses on improving hearing recovery and patient quality of life, particularly in cases of idiopathic sudden sensorineural hearing loss 1.
Importance of Prompt Recognition and Management
Prompt recognition and management of sensorineural hearing loss are crucial to improve hearing recovery and patient quality of life 1. The guideline update group recognized that patients enter the health care system with sudden hearing loss as a nonspecific primary complaint, and therefore, the initial recommendations address distinguishing sensorineural hearing loss from conductive hearing loss at the time of presentation with hearing loss 1.
From the Research
Definition of Sensorineural Hearing Loss
- Sensorineural hearing loss is the most common type of hearing impairment worldwide, arising from damage to the cochlea or auditory nerve 2.
- It encompasses various pathologies in both the inner ear and the auditory nerve, accounting for approximately 70% of hearing impairment cases 3.
Causes and Characteristics
- Sensorineural hearing loss can be caused by genetic mutations, environmental insults such as noise, ototoxic substances, and hypoxia, and its prevalence increases dramatically with age 2.
- The condition is characterized by insensitivity to weak sounds, loudness recruitment, poor perception of pitch and auditory space, and difficulty understanding speech, particularly in the presence of background noise 2.
- It can range from mild variants with exclusive deficits of temporal processing to complete deafness, often resulting in poor speech recognition out of proportion to the pure tone threshold 3.
Treatment and Management
- Sensorineural hearing loss is usually incurable, and treatment focuses on restoring the audibility of sounds made inaudible by hearing loss using either hearing aids or cochlear implants 2.
- Research is being conducted to develop therapeutic interventions to regenerate hair cells as a treatment for hearing loss, including gene therapy and small molecule delivery to the inner ear 4.
- Cochlear implants are a treatment option for individuals with severe, profound, or moderate sloping to profound bilateral sensorineural hearing loss who receive little or no benefit from hearing aids 5.