GRAS 45BB-14 KEMAR for High-Frequency Test of Ear- and Headphones, 2-Ch CCP

Connection: Constant Current Power (0 V/CCP)
Channel(s): 2
ANSI: S3.36, S3.25
IEC: 60318-4
ITU-T Rec. P.57 Type 3.3
based on ITU-T Rec. P.58

GRAS 45BB-14 KEMAR for High-Frequency Test of Ear- and Headphones, 2-Ch CCP

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 GRAS 45BB 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 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 45BB KEMARs consist of the same basic 45BB 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 45BB 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 45BB-14 is a KEMAR head and torso for 2-channel ear and headphone test, with prepolarized high-frequency ear simulators and anthropometric 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 45BB-14 are the GRAS RA0402 Prepolarized High-Resolution Ear Simulator and the KB5000/KB50001 Anthropometric Pinnae.

The High-Frequency Ear Simulator
The acoustic input impedance of the RA0402 closely resembles that of the human ear and, as a result, loads a sound source in very much the same way.  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.

The RA0402 mitigates the limited usefulness of the standard IEC60318-4 ear simulator above 10 kHz. The steep resonance at 13.5 kHz has been replaced by a much-damped resonance and the useful frequency range is now extended to 20 kHz within a narrow tolerance band. It complies with IEC60318-4 and its acoustic transfer impedance is within the tolerance band specified by IEC60318-4. From 10 to 20 kHz the transfer impedance is within ± 2.2 dB, resulting in much-improved repeatability. Also, realistic THD measurements are now possible.

It is measured and calibrated according to IEC60318-4 and ITU-T Recommendation P.57 and delivered with a calibration chart specifying its sensitivity and frequency response.

It is delivered with a built-in GRAS 40AO 1/2" prepolarized pressure microphone.

Read more about RA0402 here.

The Anthropometric Pinna
Compared to the standardized pinna, the anthropometric pinna embodies a number of improvements to the concha and ear canal, combined with increased collapsibility of the helix, and improved mounting. It is made of soft silicone, 35 Shore OO hardness.

The external shape of the pinna is identical to that of the standardized KEMAR pinna, but concha and ear canal have been modified so that they closely mimic the properties of a real human ear. The ear canal has been extended and is now an integral part of the pinna which seals directly against the ear simulator. Like the human ear, the ear canal has the 1st and 2nd bend, and the interface with the concha is oval. Fit and insertion consistency are much improved over the cylindrically or conically shaped ear canal extensions that are used with the standard pinna.

The flexibility of the outer ear has been improved, and when mounting supra-aural and circum-aural headphones the pinna now collapses against the head very much like a human ear.

In addition to the traditional push mounting from the outside, the pinna is secured with two screws from the inside of KEMAR's head. These two screws ensure that the pinna is held firmly in place. Therefore, it seals perfectly against the ear simulator and the head, and it is now possible to mount and dismount DUTs repeatedly without compromising the seal.

Read more about the Anthropometric Pinnae here.

Typical Applications

The anatomical shape of the pinna makes it possible to achieve a very good fit and sealing with anatomically shaped in-ear transducers. Controlling the insertion depth is easy, leading to good insertion consistency and highly improved repeatability and accuracy of measurements. The improved fit and seal also mean that the low-frequency response is improved. It will allow you to reproduce bass notes, as well as effectively measure (active & passive) attenuation.

With the high-frequency ear simulator, it is now possible to make realistic measurements up to 20 kHz. Therefore, the 45BB-14 KEMAR is ideal for accurate and repeatable testing of hearing aids, headphones, earphones, and in-ear hearing protectors. Read more about the advantages of the high-frequency ear simulator here.

Performance and warranty

KEMAR is made of components from our standard portfolio, all manufactured of high-quality material and branded parts that were chosen and processed to ensure life-long stability and robustness. This enables us to offer 2 years warranty against defective materials and workmanship.
Exceptions: Microphones included in KEMAR as for these our normal 5-year warranty apply. The warranty period for cables is 6 months.

Specifications

Connector type
BNC
Set sensitivity @ 250 Hz (±2 dB)
mV/Pa
12.5
Set sensitivity @ 250 Hz (±2 dB)
dB re 1V/Pa
-38.5
Theoretical dynamic range lower limit with GRAS preamplifier
dB(A)
25
Theoretical dynamic range upper limit with GRAS CCP preamplifier
dB
150
Resonance frequency
kHz
13.5
Temperature range, operation
°C / °F
-30 to 60 / -22 to 140
Temperature range, storage
°C / °F
-40 to 65 / -40 to 149
Humidity range non condensing
% RH
0 to 95%
ANSI standard
S3.36, S3.25
IEC standard
60318-4 (former 60711), 60318-7 (former 60959)
ITU-T recommondations
P. 58
Weight
g / oz
11.45 k / 404

Ordering info

Included items

GRAS 45BB

KEMAR Head & Torso, Non-configured

GRAS KB5000

Large Right Anthropometric Pinna 35 Shore OO

GRAS KB5001

Large Left Anthropometric Pinnar 35 Shore OO

GRAS RA0402

Prepolarized High-Frequency Ear Simulator ( 2 pcs)

GRAS GR1874

Ear Simulator Holder

GRAS GR0408

External Ear Canal

GRAS GR0409

Union Nut

GRAS 26CS

1/4" CCP Short Preamplifier (2 pcs)

GRAS RA0001

Adapter for 1/2" Microphone and 1/4" Preamplifier (2 pcs)

GRAS AA0018-S

Microdot-BNC Cable, 35 cm (2 pcs)

GRAS AA0035

BNC-BNC Cable, 3 m (2 pcs)

 

Optional items

Power Modules for Pre-polarized Ear Simulators and Microphones

GRAS 12AL

1-Channel CCP Power Module with A-weighting filter 

GRAS 12AQ

2-Channel Universal Power Module with signal conditioning and PC interface

 

For Ear Simulator Calibration

GRAS 42AP

Intelligent Pistonphone (250 Hz or 251.2 Hz, 114 dB +/- 0.05 dB)

GRAS 42AA

Pistonphone (250 Hz, 114 dB +/- 0.08 dB)

 

Pinna Simulators

GRAS KB5000

Large Right Anthropometric Pinna 35 Shore OO

GRAS KB5001

Large Left Anthropometric Pinnar 35 Shore OO

GRAS KB0060

KEMAR Small Right Straight Pinna 55 Shore OO

GRAS KB0061

KEMAR Small Straight Pinna 55 Shore OO

GRAS KB0065

KEMAR Large Straight Pinna 55 Shore OO 

GRAS KB0066

KEMAR Large Left Straight Pinna 55 Shore OO

GRAS KB1060

KEMAR Small Right Straight Pinna 35 Shore OO 

GRAS KB1061

KEMAR Small Left Straight Pinna 35 Shore OO

GRAS KB1065

KEMAR Large Right Straight Pinna 35 Shore OO 

GRAS KB1066

KEMAR Large Left Straight Pinna 35 Shore OO

GRAS KB0090

KEMAR Large Right Tapered Pinna (VA-Style/SQ) 55 Shore OO 

GRAS KB0091

KEMAR Large Left Tapered Pinna (VA-Style/SQ) 55 Shore OO

GRAS KB1090

KEMAR Large Right Tapered Pinna (VA-Style) 35 Shore OO 

GRAS KB1091

KEMAR Large Left Tapered Pinna (VA-Style) 35 Shore OO 

 

Ear Mould Simulators

GRAS KB0110

Ear Mould Simulator for 2 mm Inner diameter tubing 

GRAS KB0111

Ear Mould Simulator for 3 mm Inner diameter tubing

 

Ear Canal Extension and Microphone Holder Kits (kits with 2 pcs and O-rings)

GRAS RA0237

Straight Ear Canal Extension Kit for KEMAR 

GRAS RA0238

VA-tapered Ear Canal Extension Kit for KEMAR 

GRAS RA0239

Ear Canal Extension Kit w. silicone lining for KEMAR

GRAS RA0240

Holder for long 1/2" Microphone Kit for KEMAR 

GRAS RA0241

Holder for short 1/2" Microphone Kit for KEMAR

GRAS RA0243

Holder for 1/4" Microphone Kit for KEMAR

GRAS RA0244

O-ring kit for KEMAR 

GRAS RA0249

Straight Ear Canal Extension Kit for KEMAR, made of POM, for binaural hearing aid test

GRAS RA0250

Tapered Ear Canal Extension Kit for KEMAR,made of POM, for binaural hearing aid test

 

KEMAR Retrofit Kit for Binaural Hearing Aid Test

GRAS RA0251

KEMAR Retrofit Kit for Binaural Hearing Aid Test.

The Kit includes Ear Holder Plates, mounting bolts and the RA0249 and RA0250 Ear Canal Extension Kits.
Included items are made of POM, Nylon and Teflon.

 

Extension Cables

GRAS AA0034

BNC-BNC Cable, 2 m

GRAS AA0035

BNC-BNC Cable, 3 m 

GRAS AA0036

BNC-BNC Cable, 5 m

GRAS AA0037

BNC-BNC Cable, 10 m 

GRAS AA0039-CL

BNC-BNC Cable, Customized Length, xxxx cm 

 

Flight Case

GRAS KM0094

 PELI Case for KEMAR

 

Simulation Model of KEMAR

GRAS KB3000

3D Simulation Model of KEMAR with large pinnae, stp file

GRAS KB3001

3D Simulation Model of KEMAR with small pinnae, stp file

GRAS KB3002

3D Simulation Model of KEMAR with anthropometric pinnae, stp file

 

Stand for KEMAR

GRAS AL0026

 Loudspeaker stand for KEMAR, Ø 35 mm

 

Miscellaneous

GRAS KB0000

KEMAR Handbook 

GRAS KB0010

T-Shirt for KEMAR 

 GRAS Sound & Vibration reserves the right to change specifications and accessories without notice.

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