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KEMAR, the Knowles Electronics Manikin for Acoustic Research, is a head-and-torso acoustic simulator used to measure how sound interacts with an approximately human-sized listening geometry. Its external ears, ear-canal system and acoustic loads make it more informative for many hearing-device tests than a microphone placed alone in free space. The manufacturer's description specifies representative adult dimensions and ear-simulation properties. ^[ref]

An original manikin paper by M. D. Burkhard and R. M. Sachs appeared in 1975. Later studies used KEMAR to investigate device coupling as well as the surrounding sound field.^[ref]

For example, Abhijit Kulkarni and H. Steven Colburn repeatedly placed headphone cushions on a KEMAR and measured the resulting headphone transfer function. Repositioning changed the response, complicating compensation by a single fixed inverse filter. The experiment demonstrates that the ear–device interface is part of the acoustic system, rather than an incidental mounting detail.^[ref]

An invented measurement comparison makes the meaning concrete. If the same electrical drive produces pressures of 0.020 and 0.010 pascal at one measurement frequency in two fittings, their sound pressure levels differ by $20{\log }_{10}2\approx 6.02$ decibels. This is a fit-dependent response difference at a specified point, not an automatic judgment of perceived loudness or device quality.

A standardized manikin supports reproducible comparisons but does not reproduce every listener's ear geometry, physiology or perception. Conclusions should specify the simulator configuration and measurement conditions.

M. D. Burkhard coauthored, with R. M. Sachs, a 1975 paper describing an anthropometric manikin for acoustics research. Such instruments provide a reproducible physical stand-in for measurements affected by the shape of a listener's head and torso.^[ref]

KEMAR provides the concrete apparatus example. Its documented configurations combine a head and torso with external-ear shapes, canal extensions and ear simulators for testing headphones and related equipment. The manufacturer describes these as approximations to human acoustic properties.^[ref]

A microphone alone measures the sound pressure at its position; placing it in a representative physical arrangement changes the experiment to include the effects of that arrangement. Repeatability of a manikin measurement does not imply that its response equals the response of every individual listener. Modern configurations also should not automatically be attributed to the original 1975 instrument.

R. M. Sachs coauthored, with M. D. Burkhard, a 1975 description of an anthropometric manikin for acoustics research. The contribution addressed a measurement problem: a test fixture should represent relevant features of a listener rather than merely hold a sensor in otherwise empty space.^[ref]

Current KEMAR documentation illustrates the approach with shaped head-and-torso fixtures and interchangeable ear-related components. These support controlled tests in which the apparatus configuration is recorded and reproduced.^[ref]

For a hypothetical comparison, use the same signal and fixture to test two headphone placements. A change in the measured response can then be investigated as a placement effect instead of being mixed with changes of listener anatomy. Conversely, changing an ear component changes the physical model itself. An interpretable comparison therefore specifies both the signal and the geometry.