The following are various signs and symptoms of SNHL:

• Difficulty in appropriately following conversations of two individuals.
• Difficulty in hearing loud voice.
• Inability to hear clearly in areas with loud noise.
• Inability to clearly hear in areas where there is too much of background noise.
• Men’s voice appears to be clearer than women’s voice.
• Difficulty in demarcating high pitched sounds from one another.

In addition to the above mentioned symptoms, affected individuals may also experience the following:

• Development of tinnitus, a condition characterized by ringing or buzzing sound in the ears.
• Dizziness or off balance.

• Tinnitus

  Between April 2013 and March 2017, 1126 adult patients presented to the audiology department with asymmetrical sensorineural hearing loss and/or unilateral tinnitus. [ncbi.nlm.nih.gov]

  Chronic tinnitus: relief of tinnitus (comparison 04) 4.1 Proportion of participants with improvement in tinnitus score See Analysis 4.1. [doi.org]

• Hearing Impairment

  Although TRIOBP alterations are not a frequent cause of hearing impairment, this gene should be thoroughly analyzed especially in patients with a postlingual hearing loss. [ncbi.nlm.nih.gov]

  While treatment depends on the specific condition, there are three main types of hearing impairment treatment. Wax Removal: If earwax blockage is the main cause of hearing impairment, this is an easy fix. [bluegrasshearing.com]

  impairment View Full Text Statistics from Altmetric.com aetiological investigation aetiology survey hearing impairment One in 1000 children are born with a permanent hearing impairment and 50–90% more acquire a hearing impairment in early childhood.1 [adc.bmj.com]

  There are two different types of hearing impairments, conductive hearing loss and sensorineural hearing loss. A third type is a combination of the two, called a mixed hearing loss. [dallashear.com]

  Both normally hearing and hearing-impaired subjects rated 0.125 kHz and 12 kHz tones as somewhat noise-like, independently of the existence of a DR. [doi.org]

• Sudden Hearing Loss

  Bilateral sudden hearing loss is a rare initial symptom. In this article, we report a 44-year-old male patient with bilateral sudden hearing loss and dizziness. Magnetic resonance imaging showed involvement of the bilateral vestibulocochlear nerves. [ncbi.nlm.nih.gov]

  The Academy includes hyperbaric oxygen therapy in its clinical practice guidelines for sudden hearing loss. Read the AAO-HNS Clinical Practice Guideline: Sudden Hearing Loss [PDF]. [hyperbariclink.com]

  Sudden hearing loss seriously affects patient's life and worsens his quality of life. Vascular, viral and autoimmune theory are most commonly mentioned as the cause of sudden hearing loss. [worldcat.org]

• Hearing Problem

  Hearing Aids: When hearing problems are due to damage to the inner ear, a hearing device, like a hearing aid, may be beneficial. [bluegrasshearing.com]

  You will probably be referred to an audiologist, a professional who specializes in diagnosing and treating hearing problems. The audiologist will conduct tests to determine the type and degree of your child's hearing problem. [texaschildrens.org]

  About a third of adults older than 65—and half of those older than 85—have some hearing problem. It is the third most common chronic disease among older adults. Hearing loss is more than an inconvenience. [healthinaging.org]

  […] physical factors (as in trauma-induced problems, tumors, noise damage and drug-induced hearing loss) may play a role in hearing loss. [healthcentral.com]

The following are the diagnostic procedures employed for detecting sensorineural hearing loss:

• Physical examination of the ear is done to detect infections or blockage due to physical objects or formation of ear wax.
• Tuning fork test is one of the best methods to judge SNHL. In this method, a Y-shaped metallic object is tapped and then held close to head for the individuals to hear the vibrating sound.
• Bone conduction test is specifically used for confirming SNHL. In this method, a vibrating probe is placed behind the ear. 
• Molecular genetic testing may detect congenital forms of SNHL [10].

• Macrocytosis

  A possible pathophysiological mechanism linking macrocytosis and sudden sensorineural hearing loss was identified, suggesting areas for further investigation. [ncbi.nlm.nih.gov]

The major goal of treatment is to improve the hearing ability of the affected individuals. In sensorineural hearing loss, the hearing loss cannot be completely restored. In this, since the nerve endings are damaged, the capability to hear sound clearly is greatly affected.

In mild cases, hearing aids work well for individuals suffering from mild to moderate hearing loss. For such individuals, telephone amplifiers are also known to be effective.

In severe cases, hearing aids do not work and therefore, a cochlear transplant is required. Post the procedure, the sounds appear louder but not clearer.

The prognosis of the condition greatly depends on the extent of damage to the nerve endings. Mild to moderate hearing loss may be treated with hearing aids that can help individuals to a certain extent. However, in severe cases, cochlear implants may be necessary as hearing aids may not be of much help. In many cases, no treatment regime can restore back the hearing ability.

Complications

Sensorineural hearing loss can adversely affect the quality of life. The inability to hear appropriately can give rise to the following conditions:

• Anger
• Depression
• Anxiety

SNHL is a nerve related hearing loss that basically occurs due to damage to the nerve that joins the inner ear to the brain. Several factors responsible for such a kind of hearing loss include the following:

• Immune conditions
• Exposure to high pitch sounds for longer duration on regular basis
• Certain medication that interfere with the hearing ability
• Disease such as Meniere’s disease and blood vessel disorders
• Injury 
• Infectious conditions like meningitis, mumps, measles and scarlet fever, rubella [3]
• Old age
• Tumor
• Malformation of the inner ear can lead to congenital defect
• Genetic defects [2]
• Otosclerosis
• Congenital syndromes [4]

Though the chances are rare, but SNHL can be present at birth and is caused due to genetic defect or certain infections that are transferred from the mother to the baby. A significant number of SNHL among neonates have unknown etiology [5].

The exact incidence of sensorinerual hearing loss is not known as many cases go unreported. With the limited data that is available, it can be estimated that such a type of hearing loss occurs in about 5 to 20 cases per 100,000 individuals. The average incidence of SNHL among neonates is 1.1 cases per 1000 births in the United States [6]. Men and women are affected in equal numbers by this condition.

The human ear contains tiny hairs which are also known as nerve endings that transform the sound into electric signals [7]. These signals are then carried by the nerves to the brain where they are interpreted as sound. In the condition of SNHL, the nerves that carry the information from the ear to the brain are damaged [8]. As a result, signals do not reach the brain for it to interpret the information as sound. Sequence of such events gives rise to hearing loss. In some syndromic cases of SNHLs, dysfunctional proteins have been identified in the transport of calcium and potassium ions [9].

Individuals who are exposed to loud noises for longer duration are advised to wear protective devices to prevent their ears from damage due to the loud noise. Musicians are also advised to wear ear plugs to protect their ears from the loud noise of the musical instruments. Plexiglass baffles should also be used to reduce the noise from drummer’s high hat cymbals.

Sensorineural hearing loss, abbreviated as SNHL is one of the most common type of permanent hearing loss that occurs due to damage to the inner ear and the nerve that connects the inner ear to the brain. In SNHL, the individual has great difficulty in hearing faint sounds and even sounds that are loud enough to be heard, appear unclear to the affected individuals [1]. Prolonged exposure to loud noises is one of the greatest risk factors for development of SNHL.

Definition

Sensorineural hearing loss (SNHL) is a condition characterized by loss of hearing ability due to damage to the inner ear or the nerves that transform the signals from the ear to the brain. It is the most common cause of hearing loss. It has been estimated that 90% cases of hearing loss are sensorineural in nature. The condition can be managed with hearing aids for mild cases. Severe loss of hearing would require a cochlear transplant.

Cause

Cause of SNHL include damage to the inner ear due to loud noise, certain medications, disease conditions, immunity disorders, blood vessel diseases, tumors and infections.

Symptoms

Symptoms of SNHL include inability to clearly hear conversation between 2 individuals and inability to hear in places with loud noise. Individuals with SNHL are also unable to clearly hear certain types of sound and men’s voice appears to be clearer than women’s.

Diagnosis

Diagnosis of SNHL begins with a prior physical examination of the ear to rule out infections or blockages by physical objects or ear wax. Post this, the tuning fork test is carried out to examine the extent of damage to the ear. A more sophisticated technique known as the bone conduction test is done to confirm the diagnosis of sensorineural hearing loss.

Treatment

SNHL cannot be cured; however the hearing ability can be partially restored. Hearing aids are treatment of choice for mild to moderate hearing loss. In severe cases, cochlear implants may be necessary to help individuals hear. With the implants, the hearing ability is not completely restored and the noises appear to be louder enabling the individuals to hear to some extent.

1. FDA approves first implantable hearing device for adults with a certain kind of hearing loss. US Food and Drug Administration; March 20, 2014.
2. Eisen MD, Ryugo DK. Hearing molecules: contributions from genetic deafness. Cell Mol Life Sci. Mar 2007; 64(5):566-80.
3. Saunders JE, Vaz S, Greinwald JH, Lai J, Morin L, Mojica K. Prevalence and etiology of hearing loss in rural Nicaraguan children. Laryngoscope. Mar 2007; 117(3):387-98.
4. Huang BY, Zdanski C, Castillo M. Pediatric sensorineural hearing loss, part 2: syndromic and acquired causes. AJNR Am J Neuroradiol. Mar 2012; 33(3):399-406.
5. Morzaria S, Westerberg BD, Kozak FK. Systematic review of the etiology of bilateral sensorineural hearing loss in children. Int J Pediatr Otorhinolaryngol. Sep 2004; 68(9):1193-8.
6. Mehra S, Eavey RD, Keamy DG Jr. The epidemiology of hearing impairment in the United States: newborns, children, and adolescents. Otolaryngol Head Neck Surg. Apr 2009; 140(4):461-72.
7. El-Amraoui A, Petit C. Usher I syndrome: unravelling the mechanisms that underlie the cohesion of the growing hair bundle in inner ear sensory cells. J Cell Sci. Oct 15 2005; 118:4593-603.
8. Van Camp G, SmithR. Cloned genes for nonsyndromic hearing impairment. Hereditary Hearing Loss Journal.
9. Brini M, Di Leva F, Domi T, Fedrizzi L, Lim D, Carafoli E. Plasma-membrane calcium pumps and hereditary deafness. Biochem Soc Trans. Nov 2007; 35 (pt 5):913-8.
10. Usami SI, Nishio SY, Nagano M, Abe S, Yamaguchi T. Simultaneous Screening of Multiple Mutations by Invader Assay Improves Molecular Diagnosis of Hereditary Hearing Loss: A Multicenter Study. PLoS One. 2012; 7(2):e31276.