How Hearing Loss Percentage Is Calculated in India (with Formula)

In India, a hearing disability percentage is worked out from your audiogram. The certifying medical board takes the average hearing threshold (in decibels) across key frequencies in each ear, gives more weight to your better ear, and maps that to a percentage using notified government guidelines. Higher decibel loss means a higher percentage.

What is "hearing loss percentage" and why does it exist?

The percentage is an administrative measure. It translates the audiologist's decibel readings into a single number that a medical board can use for a disability certificate and related benefits. It is not a clinical diagnosis on its own — it is a way of expressing how much hearing you have lost, in a form that schemes and employers can use consistently.

To understand where this fits in the certificate process, see our pillar guide, Hearing Disability Certificate in India: How to Apply.

What does the calculation start from?

Everything begins with a pure-tone audiogram. During the test, an audiologist finds the quietest sound you can hear at several pitches (frequencies), measured in decibels hearing level (dB HL). A higher dB number means you needed a louder sound, which means more hearing loss.

The World Health Organization describes hearing loss in grades — mild, moderate, moderately severe, severe and profound — based on these decibel thresholds. WHO also defines "disabling" hearing loss as loss greater than 35 dB in the better hearing ear. Indian disability assessment uses the same raw material (your dB thresholds) but applies its own conversion to reach a percentage.

If you do not yet have a recent audiogram, you can book a hearing test to get one.

How is the four-frequency average used?

For each ear, the assessor takes your thresholds at the main speech-relevant frequencies — commonly 500, 1000, 2000 and 4000 Hz — and averages them. This gives one representative dB figure per ear, often called the pure-tone average (PTA).

So you end up with two numbers:

• Better ear average (the ear that hears more)
• Worse ear average (the ear that hears less)

Averaging across frequencies matters because loss is rarely flat. You might hear low pitches well but struggle with high pitches, or the reverse. The average smooths this into a single value the guidelines can work with.

Why is the better ear weighted more heavily?

Because in daily life you function largely through your better ear. If one ear is near-normal, you can still follow conversation reasonably well even if the other ear is poor. The Indian method (like international handicap formulas) therefore gives the better ear far more weight than the worse ear when arriving at a percentage. Two people with the same total loss can end up with very different percentages depending on how the loss is split between the ears.

A worked example

Suppose an audiogram shows:

• Better ear four-frequency average: 50 dB
• Worse ear four-frequency average: 75 dB

Steps the board follows in principle:

1. Confirm the four-frequency average for each ear (50 dB and 75 dB here). 2. Apply the notified weighting, which leans heavily on the better ear (50 dB), so the effective figure sits closer to the better ear than to a simple midpoint. 3. Convert that weighted figure to a percentage band using the government's conversion table.

In this example the better ear sits in the moderate range, so the resulting percentage would fall in a moderate band rather than a severe one — precisely because the better ear, not the worse ear, drives the outcome.

Important: the exact coefficients and the final conversion table are set by the notified guidelines, and the certifying medical board applies them. Treat the above as an illustration of the logic, not a precise number you can quote for your certificate.

What about the 40% benchmark?

Many disability benefits in India reference a 40% threshold. Whether a given audiogram reaches 40% is a decision the certifying medical board makes, applying the notified guidelines to your specific readings. We are deliberately not giving a dB-to-40% shortcut here, because the mapping is set by government notification and can be revised, and because measurement conditions and the board's judgement both matter. Use your calculated estimate only to know roughly where you stand, then let the board issue the official figure.

When should you see an audiologist?

Get assessed promptly if:

• You struggle to follow conversation, especially in noise.
• One ear has clearly become worse than the other.
• Hearing dropped suddenly — sudden hearing loss is an emergency; seek same-day medical or ENT care, as early treatment can matter.

Age is the most common driver of gradual loss, as the NIDCD notes, but any new or one-sided change deserves a professional check. You can talk to our team to arrange an assessment.