KEMAR Head & Torso GRAS 45BB

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). The GRAS KEMAR has the same dimensions and acoustical properties as the original KEMAR from 1972 and is 100% backward compatible.
• When fitted with pinna simulator, ear canal extension, and IEC 60318-4 Ear Simulator, KEMAR closely mimics the acoustic properties of the human ear.
• KEMAR meets the international standards as specified by IEC: 60318-7 and ANSI: S3.36, S3.25.
• The 45BB KEMAR is a non-configured KEMAR – without a mouth simulator. The 45BC KEMAR is identical, except that it has a built-in Mouth Simulator. Read more about 45BC KEMAR here.

Design

Anthropometric Head and Torso

• The major difference between KEMAR and the standard commercially available head and torso simulators (HATS) is that KEMAR is built on large statistical research of the average human body – meaning that the KEMAR has the same acoustical properties as an average human, including distinct facial features. Therefore it provides acoustic diffraction similar to that encountered around the median human head and torso, both in the proximity and in the far-field. Because of its anthropometric shape, it does so more realistically than any other manikin. KEMAR is the only manikin with a changeable ear-to-shoulder ratio simulating both male and female median values.

True to the Legacy – but Improved 

• The current KEMAR 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. Today, more than 40 years after its inception KEMAR can test any device that contains both loudspeakers and microphones as well as perform binaural recordings of product sound and music.
• At GRAS, we safeguard KEMAR’s legacy, but are also continuously expanding the range of features and functionalities leading to new applications and uses – without compromising KEMAR’s original form.
• In 2013, KEMAR underwent a substantial rejuvenation that introduced major improvements to build quality, user-friendliness and configurability. KEMAR’s previous fiberglass construction was updated to a plastic composite that provides a more user-friendly and ruggedized construction. At the same time, many other improvements were introduced, making KEMAR much easier to configure, calibrate and service.

Ease of Use

• The interior of KEMAR’s head can be accessed easily by pushing a button and lifting the scalp.
• The transducers are mounted and removed by a simple snap-fit mechanism.
• Standard pinnae are push mounted from the outside. The anthropometric pinnae, however, are secured from the inside by two screws in addition to the push mounting.
• A scale around KEMAR’s neck indicates the head angle and allows for repeatable measurements.
• In most cases, calibration can be done from the outside without dismantling the ear simulator(s). However, for some configurations – with microphones and anthropometric pinnae –  dismounting of the transducers before calibration is necessary.