1 Scope
This part of IEC 60318 describes a head and torso simulator
(manikin) intended for the measurement of air-conduction hearing
aids in the frequency range from 100 Hz to 10 000 Hz. The device consists of a head
mounted on a torso that extends to the waist. The head is equipped with simulated
pinnae and with cylindrical cavities having acoustic impedance terminations and
microphones located at positions corresponding to those of the eardrums in a median
human adult. It has been designed to provide acoustic diffraction similar to that
encountered around the median human head and torso.
The device with its present pinna simulator, however, is not suitable for the measurement
of all types of hearing aids. For example, most in-the-ear (ITE) and
completely-in-the-canal (CIC) hearing aids cannot be measured correctly.
The manikin
is specified in terms of both, its geometrical dimensions and its acoustical
properties.
NOTE 1 Measurement results obtained with a manikin may differ substantially from
similar results obtained on an individual person, due to anatomical
variations.
NOTE 2 The median values of the human head and torso were drawn from the population
samples described in [5] 1.
NOTE 3 It is acknowledged that devices conforming to this part of IEC 60318 are
also used as the basis for applications extending beyond this Scope. In such
cases it is recommended that any design variations that are necessary are
documented, and that a statistical analysis of the measurement data be carried
out to determine the level of repeatability that can be achieved. It will also
be necessary to consider the relevance of the measurements made with the head
and torso simulator to the application in question.
