Calculate Pure Tone Average (PTA) from audiogram frequencies and classify hearing loss severity using WHO criteria. Enter dB HL values for each frequency.
The Hearing Loss Frequency Calculator computes your Pure Tone Average (PTA) from audiogram threshold measurements and classifies the severity of hearing loss using the World Health Organization (WHO) grading system. The PTA is the average hearing threshold at the speech frequencies (500, 1000, 2000, and 4000 Hz) and is the primary metric used to quantify hearing ability.
Audiograms measure the softest sound you can hear (threshold) at each frequency, expressed in dB HL (decibels Hearing Level). Normal hearing is 0–25 dB HL, while sounds above your threshold are inaudible. This calculator accepts thresholds at standard audiometric frequencies from 250 Hz to 8000 Hz and computes the PTA for each ear independently.
Hearing loss affects over 1.5 billion people worldwide and is the third most common chronic condition. Early identification and quantification through audiometry enables timely intervention with hearing aids, cochlear implants, or medical treatment. Whether you are a beginner or experienced professional, this free online tool provides instant, reliable results without manual computation.
Understanding your audiogram results helps you make informed decisions about hearing health. The PTA reduces a complex audiogram to a single number that indicates overall hearing ability in the speech range. WHO severity classification provides context for how hearing loss affects daily communication and guides treatment recommendations. This calculator makes audiometric data accessible to patients wanting to understand their hearing test results.
Pure Tone Average (PTA) = (threshold at 500 Hz + 1000 Hz + 2000 Hz + 4000 Hz) / 4 WHO Hearing Loss Classification (better ear PTA): • Normal: 0–25 dB HL • Mild: 26–40 dB HL • Moderate: 41–60 dB HL • Severe: 61–80 dB HL • Profound: >80 dB HL Note: Some audiologists use a 3-frequency PTA (500, 1000, 2000 Hz) for speech recognition prediction.
Result: PTA: 37.5 dB HL — Mild Hearing Loss
The PTA is (25 + 30 + 40 + 55) / 4 = 37.5 dB HL. This falls in the "Mild" category (26–40 dB), where soft speech and whispers are difficult to hear. The rising thresholds at higher frequencies suggest age-related hearing loss (presbycusis), which typically affects higher frequencies first. A hearing aid evaluation would be recommended.
Pure tone audiometry measures frequency-specific hearing thresholds. Speech audiometry includes the Speech Reception Threshold (SRT) — the softest level at which words are understood 50% of the time — and Word Recognition Score (WRS) — the percentage of words correctly identified at a comfortable volume. Tympanometry measures middle ear function. OAE (Otoacoustic Emissions) tests cochlear function. ABR (Auditory Brainstem Response) assesses the auditory nerve pathway.
Untreated hearing loss has far-reaching consequences beyond difficulty hearing. Research links it to social isolation, depression, cognitive decline, and increased dementia risk. A 2020 Lancet Commission identified hearing loss as the largest potentially modifiable risk factor for dementia. Economically, untreated hearing loss costs an estimated $750 billion annually worldwide in lost productivity and healthcare costs.
Current hearing aids use digital signal processing, directional microphones, feedback cancellation, and Bluetooth connectivity. Many models are rechargeable and nearly invisible. Over-the-counter (OTC) hearing aids became available in the US in 2022 for adults with mild-to-moderate loss, improving access and reducing cost barriers. However, severe-to-profound loss still requires prescription devices with professional fitting.
A normal audiogram shows hearing thresholds at or below 25 dB HL across all frequencies (250–8000 Hz). Younger adults often have thresholds of 0–15 dB HL. Thresholds naturally increase (worsen) with age, particularly at higher frequencies. An audiogram is considered clinically normal if the PTA is 25 dB HL or less.
Low frequencies (250–500 Hz) carry the vowel energy and bass tones in speech. Mid frequencies (1000–2000 Hz) are the core speech range where most consonants are distinguished. High frequencies (4000–8000 Hz) provide clarity and sharpness to speech sounds. Loss at different frequencies creates different communication difficulties. High-frequency loss makes speech sound "muddy" even when loud enough.
Sensorineural loss involves damage to the inner ear (cochlea) or auditory nerve — caused by aging, noise exposure, genetics, or ototoxic medications. It is generally permanent. Conductive loss involves problems in the outer or middle ear (fluid, earwax, perforation, otosclerosis) that prevent sound from reaching the inner ear. It is often medically or surgically treatable. Audiometry distinguishes them by comparing air conduction and bone conduction thresholds.
Clinical guidelines typically recommend hearing aid evaluation when PTA exceeds 25–30 dB HL, but the decision depends more on communication impact than numbers. If you regularly ask people to repeat themselves, struggle in group conversations, or increase TV volume beyond comfortable levels for others, you may benefit from amplification regardless of your exact PTA. Early adoption leads to better outcomes.
Noise-induced hearing loss is entirely preventable with proper hearing protection. The NIOSH recommended exposure limit is 85 dB for 8 hours. For every 3 dB increase, safe exposure time halves. Use ear protection for power tools (90–100 dB), concerts (100–120 dB), and firearms (140+ dB). Age-related hearing loss cannot be prevented but may be slowed by avoiding noise exposure, managing cardiovascular health, and avoiding ototoxic medications when possible.
Noise-induced hearing loss characteristically shows a dip (notch) in hearing thresholds at 4000 Hz, with recovery at 8000 Hz. This pattern is pathognomonic for noise damage, distinguishing it from age-related loss (which shows a continuous high-frequency slope without recovery). The notch occurs because the 4000 Hz region of the cochlea is anatomically most vulnerable to noise damage.