BRUEL & KJAER 4185, User Manual

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22 Ear Simulator for Telephonometry Type 4185
User Manual
Ear simulator
A device consisting of a precision acoustic coupler and an
integral calibrated microphone that accurately simulates
the acoustic impedance of the average human ear,
according to ITU-T Rec. P.57.
A Type 1 ear is used for sealed earphone measurements on
high-impedance handsets.
A Type 2 ear is required for measurements of headsets and
insert-type earphones.
A Type 3 ear is used for realistic measurements on both high
and low-impedance handsets
ERP
Ear Reference Point. The point at the entrance of the
listener's ear occupied by the centre of a telephone earcap.
This point is used as the origin in handset positioning
specifications
Handset
A rigid assembly for holding both the microphone and
earphone simultaneously to the mouth and ear,
respectively
HATS
Head and Torso Simulator. A measurement manikin
including ear and mouth simulators that provides the
correct representation of the acoustic effects around a
human head and torso according to ITU-T Rec. P.58
IEC
International Electrotechnical Commission
IEEE
Institute of Electrical and Electronics Engineers
LR
Loudness Rating. A single number, expressed in dB,
determined either subjectively or objectively, representing
the loss in a telephone system