Technology
Introduction
- The KEMAR head and torso simulator was introduced by Knowles in 1972 and quickly became the industry standard for hearing-aid manufacturers and research audiologists (visit KEMAR.us to read the full story). It is based on worldwide average human male and female head and torso dimensions. It meets the requirements of ANSI S3.36/ASA58-2012 and IEC 60318-7:2011.
- The current KEMAR Head and Torso has the same dimensions and acoustical properties as the original KEMAR, but has been developed further by GRAS to meet the industry’s demand for realistic measurements of hearing aids, headphones, and headsets. It provides acoustic diffraction similar to that encountered around the median human head and torso, both in the proximity and in the far-field.
- As all the preconfigured 45BC KEMARs consist of the same basic 45BC KEMAR Non-configured, plus a set of application-specific accessories, the full information about a given KEMAR configuration is obtained by combining the information about the 45BC KEMAR Non-configured and the information for a given configured version as found in the present text. Read about the non-configured KEMAR here.
Design
- The 45BC-1 is a KEMAR for 2-channel headset test, with externally polarized ear simulators and large straight pinnae.
- It is delivered fully configured, individually calibrated and ready for use. In addition to a system calibration certificate, a USB flash memory with simulation data is included.
- The main configuration specific components of the 45BC-1 are the 44AA Mouth Simulator, the RA0045 Ear Simulator According to 60318-4 and the KB0065/KB0066 Large Straight Pinnae.
- The 44AA Mouth Simulator according to ITU-T Rec. P51 with built-in power amplifier
- The maximum continuous signal the mouth can produce in 1/3-octave bands is 100dB re. 20µPa in the frequency range of 100Hz to 16kHz. Its loudspeaker accepts an external signal either directly or via its own built-in power amplifier (when power is applied).
- The 60318-4 Ear Simulator
- The acoustic input impedance of the RA0045 Ear Simulator closely resembles that of the human ear and, as a result, loads a sound source in very much the same way.
- It complies with IEC 60318-4 and is measured and calibrated according to ITU-T P.57. It embodies a number of carefully designed volumes connected via well-defined and precisely tuned resistive grooves. In an equivalent electrical circuit, capacitors would represent the volumes, and inductance and resistance would represent respectively air mass and air flow within the resistive groves.
- Read more about the RA0045 Ear Simulator.
- The KB0065/KB0066 Pinnae
- The KB0065 and KB0066 are large straight pinnae for use with a straight ear canal extension. The hardness is 55 Shore 00. They comply with the IEC and ITU-T recommendations.
- Other accessories for this configuration are listed in the Ordering Info tab.