---
title: "Human vibration"
description: "Vibration transmitted to people: the ISO 8041-1 weightings and ISO 2631-1 whole-body metrics, hand-arm exposure per ISO 5349 with the Directive 2002/44/EC action and limit values, and the ISO 2631-5 spinal-response model for repeated shocks."
---

Vibration transmitted to a person is evaluated with a measurement chain
deliberately parallel to a sound level meter's: the acceleration is
**frequency-weighted** to reflect how the body responds at each frequency,
reduced to a **weighted r.m.s.** value or a dose, combined across axes, and
normalised to a **daily exposure** that regulation can act on. The two pages
of this section cover the general chain and the special case that breaks it.

[Human Vibration](/phonometry/guides/human-vibration/) is the general chain.
It covers the whole-body and hand-arm frequency weightings of **ISO 8041-1**,
the weighted r.m.s. acceleration and the running and dose measures of
**ISO 2631-1** (MTVV, VDV, MSDV, crest factor) that flag shocks a plain
r.m.s. would hide, vibration in buildings per ISO 2631-2, the hand-arm
vibration total value and daily exposure A(8) of **ISO 5349-1/-2**, and the
exposure action and limit values of **Directive 2002/44/EC** that make A(8)
legally meaningful.

[Multiple-shock whole-body vibration (ISO 2631-5)](/phonometry/guides/multiple-shock-vibration/)
handles exposures the r.m.s. philosophy underestimates: repeated mechanical
shocks from off-road vehicles, high-speed craft or earth-moving machinery,
which load the lumbar spine far beyond what their energy average suggests.
**ISO 2631-5:2018** models the seat-to-spine transfer explicitly, accumulates
a dose from the response peaks, and converts it into compressive stress on the
vertebral endplates and a probability of lumbar injury over a working life.

Use ISO 2631-1 metrics first; when the crest factor or the VDV warns that
shocks dominate, the ISO 2631-5 model is the dedicated follow-up. The
measurement front-end (weighting filters, band analysis) is shared with the
[core signal analysis](/phonometry/guides/sections/core-signal-analysis/)
section.

## Pages in this section

- [Human Vibration](/phonometry/guides/human-vibration/): ISO 8041-1
  weightings, ISO 2631-1 r.m.s. and dose measures, ISO 5349 daily exposure
  A(8) and the Directive 2002/44/EC values.
- [Multiple-shock whole-body vibration (ISO 2631-5)](/phonometry/guides/multiple-shock-vibration/):
  the spinal-response model, acceleration dose and probability of lumbar
  injury.
