Hearing Loss Calculator — dB Loss & Severity Grade
Enter your audiogram thresholds to calculate average hearing loss in decibels and see whether it falls in the mild, moderate, or severe range.
Reviewed by Rahul Singh, Health & Wellness Specialist
Formula
PTA = (500 Hz + 1000 Hz + 2000 Hz) / 3 | Monaural % = (PTA - 25) x 1.5 | Binaural = (5 x Better + Worse) / 6
Where PTA = Pure Tone Average across speech frequencies, Monaural impairment uses 25 dB as the low fence and 1.5% per dB above it, and Binaural impairment weights the better ear 5:1 against the worse ear per AMA guidelines.
Worked Examples
Example 1: Mild Bilateral Hearing Loss Assessment
Problem:Left ear: 500 Hz = 25 dB, 1000 Hz = 30 dB, 2000 Hz = 35 dB, 4000 Hz = 45 dB. Right ear: 500 Hz = 20 dB, 1000 Hz = 25 dB, 2000 Hz = 30 dB, 4000 Hz = 40 dB. Age 55.
Solution:Left PTA = (25 + 30 + 35) / 3 = 30.0 dB (Mild loss)\nRight PTA = (20 + 25 + 30) / 3 = 25.0 dB (Slight loss)\nBetter ear PTA = 25.0 dB\n\nMonaural Impairment Left: (30 - 25) x 1.5 = 7.5%\nMonaural Impairment Right: (25 - 25) x 1.5 = 0.0%\nBinaural: (5 x 0.0 + 7.5) / 6 = 1.25%\n\nHigh-frequency slope Left: 45 - 25 = 20 dB (significant)\nHigh-frequency slope Right: 40 - 20 = 20 dB (significant)\nAge-expected 4000 Hz threshold: 22.5 dB (both ears worse than expected)
Result:Left: Mild (PTA 30.0 dB) | Right: Slight (PTA 25.0 dB) | Binaural impairment: 1.25%
Example 2: Moderate Asymmetric Hearing Loss
Problem:Left ear: 500 Hz = 45 dB, 1000 Hz = 50 dB, 2000 Hz = 55 dB, 4000 Hz = 65 dB. Right ear: 500 Hz = 20 dB, 1000 Hz = 20 dB, 2000 Hz = 25 dB, 4000 Hz = 35 dB. Age 60.
Solution:Left PTA = (45 + 50 + 55) / 3 = 50.0 dB (Moderate loss)\nRight PTA = (20 + 20 + 25) / 3 = 21.7 dB (Slight loss)\nAsymmetry = |50.0 - 21.7| = 28.3 dB (SIGNIFICANT - medical evaluation needed)\n\nMonaural Left: (50 - 25) x 1.5 = 37.5%\nMonaural Right: (21.7 - 25) x 1.5 = 0%\nBinaural: (5 x 0 + 37.5) / 6 = 6.25%\n\nSpeech Recognition estimate: Left ~70%, Right ~95%\nRecommendation: MRI to rule out acoustic neuroma
Result:Left: Moderate (PTA 50.0 dB) | Right: Slight (PTA 21.7 dB) | Asymmetric - needs medical evaluation
Frequently Asked Questions
What do the different degrees of hearing loss mean practically?
Normal hearing (0-15 dB PTA) means you can hear all speech sounds without difficulty. Slight loss (16-25 dB) may cause you to miss soft speech or whispers. Mild loss (26-40 dB) makes it difficult to hear soft or distant speech, especially in noisy environments, and you may frequently ask people to repeat themselves. Moderate loss (41-55 dB) means conversational speech must be loud to be heard, and you will struggle significantly without hearing aids. Moderately severe loss (56-70 dB) requires amplification for most conversations. Severe loss (71-90 dB) means you can only hear very loud sounds or amplified speech. Profound loss (91+ dB) means you cannot hear speech even with amplification and may rely primarily on visual communication or cochlear implants.
What is the AMA binaural hearing impairment calculation?
The American Medical Association (AMA) method for calculating binaural hearing impairment is used for disability determinations, workers compensation claims, and legal proceedings. First, monaural (single ear) impairment is calculated as (PTA - 25) x 1.5 percent, where 25 dB represents the low fence (minimum threshold for impairment) and the result is capped between 0 and 100 percent. Then binaural impairment is calculated using the formula (5 x better ear percentage + worse ear percentage) / 6, which weights the better ear five times more heavily because it contributes more to functional hearing. For example, if the better ear has 10 percent monaural impairment and the worse ear has 40 percent, binaural impairment equals (5 x 10 + 40) / 6 = 15 percent. This weighting reflects that losing hearing in one ear while the other functions well has less overall impact than equal bilateral loss.
What causes high-frequency hearing loss and what does it sound like?
High-frequency hearing loss, characterized by elevated thresholds at 4000 Hz and above with relatively normal low-frequency hearing, is the most common pattern of hearing loss. It is primarily caused by noise exposure (occupational or recreational), aging (presbycusis), and certain ototoxic medications. The audiogram shows a downward slope from low to high frequencies, often called a ski-slope pattern. Practically, this means you can hear the loudness of speech but miss clarity because high-frequency consonant sounds like s, f, th, sh, and h become inaudible. People with this pattern often say others seem to mumble or that they can hear but not understand. Background noise becomes especially problematic because the brain cannot distinguish speech consonants from ambient noise. This pattern is the most successfully treated with hearing aids.
What is asymmetric hearing loss and why is it significant?
Asymmetric hearing loss occurs when there is a significant difference in hearing thresholds between the two ears, typically defined as a PTA difference greater than 15 dB or a threshold difference greater than 20 dB at any single frequency. While symmetric hearing loss is usually caused by age or general noise exposure, asymmetric loss can indicate underlying medical conditions that require investigation. These include acoustic neuroma (a benign tumor on the hearing nerve), Meniere disease, sudden sensorineural hearing loss, or middle ear pathology affecting one side. Audiologists and ENT physicians will typically recommend additional testing such as MRI imaging when asymmetric hearing loss is detected. Unilateral or asymmetric loss also creates practical challenges with sound localization and understanding speech in noise, because the brain relies on comparing inputs from both ears to filter and locate sounds.
References
Reviewed by Rahul Singh, Health & Wellness Specialist · Editorial policy