Centre for Hearing Evaluation, Conservation & Restoration

Hearing restoration is a process of restoring hearing in patients (very young children to adults- any age group) even with total hearing loss. MERF ISH is one of the leading centers for hearing restoration in the world. The clinic functions at different levels of assessment, treatment and management of disorders related hearing. The “state of the art” infrastructure with cutting-edge technology symbiozed with customized protocols, uncompromised ethics, work culture and professional expertise makes this clinic unique and one of the best in the world. Students and patients from all over the world visit MERF and MERF ISH for both learning and treatment. MERF & MERF ISH has established implantation centers across India and rest of the world
First surgery for hearing restoration was performed in 1997 in MERF using Cochlear Implant, since then MERF has performed several thousands of Cochlear Implants to restore hearing in very young children and adults with hearing loss. MERF and MERF ISH have pioneered the art of hearing restoration in all kinds of anomalies causing hearing loss from moderately severe to profound degree. This made MERF & MERF ISH as center of excellence in hearing restoration. MERF & MERF ISH has been the trend setter in hearing restoration in this part of the world


  • First to perform and publish CI in older pre-lingual with JLN syndrome, since then several patients with JLN syndrome were restored with hearing.
  • In India, first to perform, introduce and demonstrate a new technology and technique using “Contour Implant”
  • First to restore hearing in patients with assymetric hearing loss.
  • First in India and South & South East Asia to perform Auditory Brainstem Implant to restore hearing in patients with NF2.
  • First in Asia to perform Auditory Brainstem Implant (ABI) in children with absent inner ear/nerve, and now the pioneering center for ABI in children. MERF ISH & MERF is the third biggest ABI center in the world. Students of MERF ISH are the only students to have opportunity to observe, earn and experience this most sophisticated procedure. This experience and exposure makes them one of the sought after professionals in the country. MERF ISH has produced by far the best results in children with ABI

Newborn Hearing Screening:
MERF ISH has established Universal Newborn Hearing Screening programs in many hospitals in Chennai and other cities in India. MERF ISH UNHS program is customized to suite the population, culture and the system to meet the standards in NHS.

Facilities for Diagnosis of Hearing Disorders: MERFISH is equipped with all the cutting edge technology to assess and evaluate the degree of hearing loss , type of hearing loss and auditory disorders.

Subjective Test:Psycho acoustic test:- Pure Tone Audiometry ( BOA, Play Audiometry, VRA, Functional gain assessment).,

Objective Test:Electrophysiological Test: ECochG, Acoustic ABR, Electrically Evoked ABR -Trans tympanic/Promontary stimulation, Intra Cochlear Electro-Cochlear Graphy, Cortical Auditory Response

Physiological Test: ( Wide band Tympanometry, OAE, Acoustic & Non-acoustic reflexometry)

Hearing Aid Fitting /Optimization:
Hearing Aid Optimization is an art which is blended with data, technique, procedure, life style and counseling to make the best out of the hearing aids. MERF ISH has the infrastructure, expertise and technology to fit the hearing to suit your needs. We are equipped with the latest technology hearing aid analyzer which can assess the functioning of the hearing in all parameters including in-situ measurement. At the same time the information from the analyzer will provide adequate information to optimize the parameters to suit your hearing needs. MERF ISH also has other measures to assess the benefit of the hearing aid using both psycho acoustical, electrophysiological data. Cortical Auditory Evoked Potentials (HEAR Lab) developed at National Acoustic Laboratory (NAL), Australia is used to verify the hearing aid benefit in very young children, based on the data the hearing aid can be programmed adequately to suit the need of the child.

HEAR Lab is a fantastic tool used widely in many countries, MERF IS is the only institute which ahs HEAR Lab in India.

Audiometric Evaluations: Accurate Hearing Assessment for All Ages

Discover the importance of audiometric evaluations in diagnosing and managing hearing loss. Learn about the different types of tests, preparation, and what to expect during the process. Ensure optimal hearing health for yourself and loved ones.

Why is audiometry performed?

An audiometry test determines your hearing ability. You may undergo this as part of a routine examination or if you exhibit indications of hearing impairment.

Some common reasons why people lose their hearing are:

  • Problems at birth
  • Getting ear infections often
  • Inherited problems like otosclerosis (abnormal bone growth in the ear)
  • Injuries to the ear
  • Inner ear diseases (e.g., Ménière's disease, autoimmune inner ear disease)
  • Exposure to loud noises regularly
  • A perforated eardrum

Hearing loss can occur due to ear injuries or long-term exposure to loud noises. For example, attending a concert with sound levels of 85 dB can damage hearing within a few hours. If you're regularly exposed to loud music or noise in workplaces, it's a good idea to wear foam earplugs to protect your ears.

How sensorineural hearing loss occurs

Sensorineural hearing loss happens when hair cells in the cochlea malfunction. The cochlea converts sound waves into nerve signals sent to the brain. Damage to the nerve or brain areas that process sound can also result in this type of hearing loss, which is often permanent. The severity can range from mild to severe.

How to get ready for an audiometry test

There is no special preparation needed for an audiometry test. Just arrive on time and follow the audiologist's instructions.

The risks of audiometry

Audiometry is a non-invasive procedure, so there are no associated risks.

How is hearing evaluated?

Audiometry consists of multiple tests. A pure tone test measures the softest sounds you can hear at various frequencies. You'll wear headphones connected to an audiometer that plays tones and words. Your audiologist will test each ear separately by playing sounds and asking you to indicate when you hear them.

Another test evaluates how well you understand speech against background noise. You will listen to words and repeat them back. This helps assess word recognition abilities.

A tuning fork or bone oscillator can be used to evaluate sound conduction through the bone and inner ear pathways.

Following the audiometry test

After the test, your audiologist will explain your results and recommend preventive measures (e.g., wearing earplugs) or corrective measures (e.g., hearing aids) based on your hearing ability.

Additional considerations

Additional tests like otoacoustic emission testing (OAE), which detects sounds produced by the inner ear, may be used. OAE is commonly performed in newborn screenings. If hearing loss is suspected to be caused by an acoustic neuroma, an MRI of the head may be required.

A note from Merfish Clinic

An audiometry test can determine if you have hearing loss. You're not alone—more than 30 million Americans report hearing difficulties. Most hearing loss develops gradually over time. If you notice difficulties in understanding speech, consider getting a hearing test.

If you're concerned about your hearing, contact your primary care provider for a referral to an audiologist.

Location: Royapettah High Rd, Chennai

Electrophysiological Testing

An EP study, or electrophysiology study of your heart, is a test that examines your heart’s electrical activity. A healthcare provider uses this information to diagnose and treat abnormal heart rhythms. This invasive test uses catheters that go into your heart to capture its signals. In some cases, providers can address the problem during the EP study.

Electrophysiological tests offer a non-invasive way to assess the function of the inner ear and auditory nerve. These tests are particularly useful in diagnosing hearing loss, identifying the underlying cause, and monitoring disease progression.

Otoacoustic Emissions (OAE) Testing

OAE testing measures the tiny sounds produced by the inner ear in response to sound stimuli. These sounds, known as otoacoustic emissions, are generated by the outer hair cells of the cochlea. By analyzing the characteristics of these emissions, audiologists can assess the health and function of the cochlea.

Auditory Brainstem Response (ABR) Testing

ABR testing measures the electrical activity of the auditory nerve and brainstem in response to sound stimuli. Electrodes are placed on the scalp to record the brain's response to sound, providing valuable information about the auditory pathway. ABR testing is especially useful for diagnosing hearing loss in infants and young children, as well as in individuals who are unable to cooperate with traditional hearing tests.

Vestibular Testing

The vestibular system, located within the inner ear, plays a crucial role in balance and spatial orientation. Vestibular testing assesses the function of the vestibular system and can help diagnose conditions such as vertigo, dizziness, and imbalance.

Videonystagmography (VNG)

VNG is a test that records eye movements in response to specific stimuli, such as head movements or visual tracking tasks. By analyzing these eye movements, audiologists can identify abnormalities in the vestibular system and diagnose conditions like benign paroxysmal positional vertigo (BPPV) and vestibular neuritis.

Posturography

Posturography is a test that measures balance and stability while standing on a force platform. It helps assess the contribution of different sensory systems, including vision, vestibular, and proprioceptive systems, to balance control.

Types of Electrophysiology Procedures

Electrophysiology (EP) studies are diagnostic tests that record the electrical activity of the heart. These procedures are used to diagnose and treat various heart rhythm disorders, such as arrhythmias.

Here are some common types of EP procedures:

Diagnostic EP Studies

  • Standard EP Study: This is a common procedure that involves inserting thin, flexible catheters into a vein in the groin and threading them up to the heart. Once in place, the catheters record the electrical activity of the heart.
  • Electrocardiogram (ECG): This is a simple test that measures the electrical activity of the heart through electrodes placed on the skin.
  • Event Recorder: This device records the heart's electrical activity over a longer period, often weeks or months.

Ablation Procedures

  • Radiofrequency Ablation: This procedure uses radiofrequency energy to destroy the tissue causing the arrhythmia.
  • Cryoablation: This procedure uses extreme cold to freeze and destroy the tissue causing the arrhythmia.

Implantable Device Procedures

  • Pacemaker Implantation: This procedure involves implanting a small device under the skin to regulate the heart rate.
  • Implantable Cardioverter-Defibrillator (ICD) Implantation: This procedure involves implanting a device that can deliver an electric shock to the heart to correct a dangerous rhythm.

Merfish Clinic: Your Premier Choice for Electrophysiological Testing in Chennai

Merfish Clinic is committed to providing the highest quality electrophysiological testing services in Chennai. Our experienced audiologists utilize state-of-the-art technology to accurately diagnose and treat hearing disorders. By offering a comprehensive range of tests, including OAE, ABR, VNG, and posturography, we provide personalized care to meet each patient’s unique needs.

Take the First Step: Contact us to schedule a consultation and learn more about our services.