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Hearing Aid Gain Calculator

Work out hearing aid gain instantly with clear inputs, formula shown and shareable results.

About Hearing Aid Gain Calculator

Applies the classic linear prescription rules — half gain, third gain and Berger — to a hearing threshold and shows the resulting output level.

Formula

Linear gain rules

Gain = threshold x factor, with 0.5 for the half gain rule, 0.33 for the third gain rule and 0.6 for Berger; output = input level + gain

Worked example

With the default values below, Hearing Aid Gain Calculator returns Prescribed insertion gain of 30.0. Change any input above and every figure here is recalculated in your browser.

Inputs used

Hearing threshold at the frequencyaccepts 10–120 dB HL
60 dB HL
Prescription ruleone of Half gain rule, Third gain rule, Berger (0.6 x threshold)
Half gain rule
Input speech levelaccepts 40–90 dB SPL
65 dB SPL

Results

Prescribed insertion gain
30.0 dB
Output for the stated input
95.0 dB SPL
Gain factor applied
0.500
Loudness check
Output within the usual comfortable range

Step by step

  1. 1Values used
  2. 2Linear gain rules
  3. 3Prescribed insertion gain= 30.0 dB
  4. 4Output for the stated input= 95.0 dB SPL
  5. 5Gain factor applied= 0.500
  6. 6Loudness check= Output within the usual comfortable range

Assumptions and limits

  • The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax or fees or charges into account.
  • Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
  • Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.
  • This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.

Frequently Asked Questions

Are these rules still used?

They are teaching and sanity-check rules; modern fittings use NAL-NL2 or DSL v5 nonlinear prescriptions.

Why not prescribe full gain?

Full gain would make loud sounds uncomfortable and does not match how loudness perception recruits in sensorineural loss.

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