GRAS 45BB-12 KEMAR with Anthropometric Pinna for Low-noise Ear- and Headphone Test, 2-Ch LEMO

Connection: Traditional Power Supply (200 V/LEMO)
Channel(s): 2
ANSI: S3.36
Based on IEC 60318-7
Based on ITU-T Rec. P.58

GRAS 45BB-12 KEMAR with Anthropometric Pinna for Low-noise Ear- and Headphone Test, 2-Ch LEMO

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-12 is a KEMAR configured for 2-channel low-noise test of ear and headphones.

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 components of the 45BB-12 are the GRAS 43BB Low-noise Ear Simulator Systems and the KB5000/KB5001 anthropometric pinnae.

The 43BB Low-noise Ear Simulator System

Basically the 43BB consists of an IEC 60318-4 (711) Ear Simulator and a 40HT Low-noise Microphone System.

The built-in microphone is the 40AH Low-noise Ext. Polarized Pressure Microphone which has a specially reduced noise floor in order to achieve a large dynamic range.

Below 10 kHz, the frequency response is identical to that of a standard IEC 60318-4 ear simulator. Above 10 kHz, the differences in the microphone diaphragm impedance results in substantial differences. The standard ear simulator has a high-Q resonance around 13.5 kHz related to the length of the ear canal and the diaphragm impedance. In the low noise version of the ear simulator the single high-Q resonance is replaced by two resonances. Part of the design of the low noise microphone is a filter unit that controls the mechanical resonance of the low noise microphone. The combination of the filter and the low damping of the diaphragm cancels out the high peak of the resonance in the simulator.

The preamplifier is the 26HG which is similar to the GRAS 26AC ¼” Standard Preamplifier, but with a 40 GΩ input impedance to enable low-level noise measurements. It has an integrated lightweight cable terminated in a 7-pin LEMO connector that plugs into the 26HT Gain and Filter Unit.

To complete the system, a special power module is part of the delivery, i.e. the12HF 1-Channel Power Module for Low-noise Systems.

Read more about the 43BB Low-noise Ear Simulator System 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 collapsability 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 screw ensure that the pinna is held firmly in place. Therefore, it seals perfectly against the ear simulator and the head, and it is therefore possible to mount and dismount DUTs repeatedly without compromising the seal.

Read more about the Anthropometric Pinnae here.

Typical Applications

45BB-12 is configured to meet the consumer electronics industry's need for R&D testing of ear and headphones, including in-ear headphones with Active Noise Cancellation.

The anatomical shape of the pinna makes it possible to achieve 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 means that the low frequency response is improved. It will allow you to reproduce base notes, as well as effectively measure (active & passive) attenuation

Because it can measure down to and below the threshold of human hearing, it can measure the influence of the electronics on the audio response of the earphones. Its low noise floor and usability above 10 kHz means that measurement results will have a strong correlation with the subjective feedback from test persons and users.

The low inherent noise of the system also means that THD and Rub & Buzz at very low levels can be investigated.

For these reasons, the 45BB-12 KEMAR is ideal for accurate and repeatable testing of headphones, earphones and in-ear hearing protectors. Also, the improved collapsibility of the pinna makes it well suited for testing of supra-aural and circumaural headphones.

Performance and warranty

KEMAR is made of components from our standard portfolio and are 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
7-pin LEMO (FGG.1B.307)
Set sensitivity @ 250 Hz (±2 dB)
mV/Pa
800
Set sensitivity @ 250 Hz (±2 dB)
dB re 1V/Pa
Theoretical dynamic range lower limit with GRAS preamplifier
dB(A)
10.5
Theoretical dynamic range upper limit with GRAS preamplifier @ +28 V / ±14 V power supply
dB
113
Theoretical dynamic range upper limit with GRAS preamplifier @ +120 V / ±60 V power supply
dB
Resonance frequency
kHz
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
Specification Conditions

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

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 Pinna 35 Shore OO

GRAS GR1874

Ear Simulator Holder

GRAS AA0035

BNC Cable, 3 m (2 pcs)

GRAS 43BB-1

Low-noise Ear Simulator System (2 pcs), each comprising:

   GRAS GR0408

External Ear Canal

   GRAS GR0409

Union Nut

   GRAS RA0234

Low-noise Ear Simulator

   GRAS 26HG

1/4" Preamplifier, with 3 m Cable

   GRAS 26HT

Filter and Gain Unit

   GRAS 12HF

Power Module

   GRAS RA0001

Right Angled Adapter for 1/2" Microphone and 1/4" Preamplifier

   GRAS AA0059

LEMO 7-pin - LEMO 7-pin Cable, 1 m

 

Optional items

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)

GRAS RA0090

94 dB Pistonphone Coupler

Cables

GRAS AA0046

3 m LEMO 7-pin - LEMO 7-pin Cable for Low-noise measuring system

GRAS AA0047

10 m LEMO 7-pin - LEMO 7-pin Cable for Low-noise measuring system

GRAS AA0053-CL

Customized length LEMO 7-pin - LEMO 7-pin Cable for Low-noise measuring system. CLXXXX= Cable length in centimeters to be specified by customer

Pinna Simulators

GRAS KB0060

KEMAR Small Right Straight Pinna 55 Shore OO

GRAS KB0061

KEMAR Small Left Straight Pinna 55 Shore OO

GRAS KB0065

KEMAR Large Right 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, 2 pcs. 

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.

 

Flight Case

GRAS KM0094

 PELI Case for KEMAR

 

Simulation Model of 45BB KEMAR

GRAS KB3000

Simulation Model of KEMAR with large pinnae

GRAS KB3001

Simulation Model of KEMAR with small pinnae

 

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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