Three tabs covering noise-induced hearing loss (NIHL) assessment.
Tab 1 — Diagnosis & quantification of a single audiogram. Enter the patient's DOB, sex, audiogram date and threshold values (HTLs) at 8 frequencies for each ear. The calculator runs both leading medico-legal methods in parallel — the Moore rM-NIHL method (military noise) and the LCB 2015 method (occupational noise) — and reports diagnosis + per-ear NIHL quantification, plus binaural averages and the Smoorenburg sentence-understanding decrement.
Tab 2 — Progression across multiple audiograms. Enter HTLs at the given frequencies for a series of audiograms, giving the date for each. The calculator applies both the Moore and LCB methods to identify the change in hearing across time.
Tab 3 — Noise exposure / NIL. Computes daily/weekly noise exposure and Noise Immission Level. Inputs: working days per year/week, years of exposure, activity, time, and the noise exposure — returns the estimate of noise exposure per day and cumulative NIL.
NIHL Assessment
Moore (rM-NIHL) — method-specific inputs
Moore only — the LCB analysis selects its own percentile by best fit at the 1 kHz and 8 kHz anchors.
LCB 2015 — method-specific input
R2(a) → 10 dB R3 bulge threshold · R2(b) → 20 dB · <90 → no LCB diagnosis.
Track the progression of NIHL across multiple audiograms over time. Enter the patient's DOB and sex once at the top, then add an audiogram row for each ear-test on each session date — typically two rows per session (one for the right ear, one for the left).
For each audiogram row, the calculator runs both Moore rM-NIHL and LCB 2015 against the patient's age at that audiogram date, using the AAHL baseline appropriate for that age. The summary panel shows the date of first positive diagnosis per method per ear and the change in 1+2+3 kHz NIHL between the earliest and latest audiograms.
Progression across audiograms
Moore (rM-NIHL) — method-specific inputs
Moore only — LCB picks its own percentile by best fit.
LCB 2015 — method-specific input
Audiograms (one row per ear per session)
Date
Label
Ear
250
500
1k
2k
3k
4k
6k
8k
Moore
LCB
Progression summary
Moore rM-NIHL
LCB 2015
Show working
How to use this calculator
Build up a typical working day from one or more noise-exposed activities. Each row needs the duration (hours per day) and the A-weighted sound pressure level (in dB(A)) during that activity. Add a hearing protector attenuation if applicable — HSE recommends a 4 dB de-rating from the manufacturer-claimed value to reflect real-world fit, which the calculator applies automatically.
Outputs: LEP,d — daily personal noise exposure, normalised to an 8-hour working day. Compared against the Control of Noise at Work Regulations 2005 Lower (80 dB(A)) and Upper (85 dB(A)) Exposure Action Values, and the Exposure Limit Value (87 dB(A) at the ear). LEP,w — weekly personal noise exposure, normalised to a 40-hour week. Useful where work patterns differ from a standard 5-day week. NIL — cumulative Noise Immission Level after N years. NIL = LEP,d + 10·log10(years). This is the exposure metric that drives the LCB R2 branch on Tab 1: NIL ≥ 100 triggers R2(a); 90–99.9 triggers R2(b); below 90 fails the LCB pathway.
Formulae from HSE JSP 375 Vol 1 Chap 25 Annex A: link.
Noise exposure & Noise Immission Level
For LEP,w calculation. Default 5.
For NIL calculation.
All durations are hours per day. The calculator computes LEP,d on the activities entered, then scales to LEP,w using days/week, then to NIL using years of exposure.