G.R.A.S. 45BC-12 KEMAR with Mouth Simulator and Anthropometric Pinnae for Low-noise Headset Test, 2-Ch LEMO

Connection: Traditional Power Supply (200 V/LEMO)
Channel(s): 2
ANSI: S3.36
Based on IEC 60318-4 and 60318-7
Based on ITU-T Rec. P.57 Type 3.3 and ITU-T Rec. P.58
Special feature: Built-in power amplifier for mouth simulator


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 G.R.A.S. 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.


The 45BC-12 is a KEMAR with mouth simulator, anthropometric pinnae and low-noise ear simulators for 2-channel low-noise headset test. 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 accessories specific for this configuration are listed in the Ordering Info tab.

The main configuration specific components of the 45BC-12 are the G.R.A.S 44AA Mouth Simulator, the G.R.A.S. 43BB Low-noise Ear Simulator System and the KB5000/KB5001 anthropometric 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 100Hz to 16kHz. Its loudspeaker accepts an external signal either directly or via its own built-in power amplifier (when power is applied).

The 43BB Low-noise Ear Simulator System

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

The built-in microphone is the 40AH Low-noise Ext. Polarized Pressure Microphone that 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 G.R.A.S. 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.

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 screws 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.

Typical Applications

45BC-12 is configured to meet the consumer electronics industry's need for R&D testing of headsets, including sets with Active Noise Cancellation.

The anatomical shape of the pinnae makes it possible to achieve excellent 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 bass 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. The improved collapsability of the pinna, and the built-in mouth simulator makes it well suited for testing of supra-aural and circumaural headsets.

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.

Connector type 3 m 7-pin LEMO
Set sensitivity @ 250 Hz (±2 dB) mV/Pa 800
Theoretical dynamic range lower limit with G.R.A.S. preamplifier dB(A) 10.5
Theoretical dynamic range upper limit with G.R.A.S. preamplifier @ +28 V / ±14 V power supply dB 113
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
IEC standard 60318-7
ITU-T recommondations P. 58
Weight g / oz 11.45 k / 404
Output impedance Ω 8
Maximum power, continuous W 10
Maximum power, pulsed 2 sec. W 50
Input impedance 20
Gain dB 10
Input signal, max. Vrms 2
Power supply, external Vdc 24
G.R.A.S. Sound & Vibration reserves the right to change specifications and accessories without notice.

Included items

G.R.A.S. 45BC

KEMAR Head & Torso with G.R.A.S. 44AA Mouth Simulator, Non-configured

G.R.A.S. KB5000

Large Right Anthropometric Pinna 35 Shore OO

G.R.A.S. KB5001

Large Left Anthropometric Pinna 35 Shore OO

G.R.A.S. GR1874

Ear Simulator Holder (2 pcs)

G.R.A.S. GR0408

External Ear Canal (2 pcs)

G.R.A.S. GR0409

Union Nut (2 pcs)

G.R.A.S. AA0035

BNC-BNC cable, 3 m

G.R.A.S. 46BD

1/4" CCP Pressure Standard Microphone Set (for mouth calibration)

G.R.A.S. 43BB-1

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

   G.R.A.S. RA0001

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

   G.R.A.S. RA0234

Low-noise Ear Simulator

   G.R.A.S. 26HG-S1

1/4" Preamplifier with 0.4 m Integrated Cable

   G.R.A.S. 26HT

Gain and Filter Unit for 40HT

   G.R.A.S. 12HF

1-Channel Power Module for Low-noise Systems

   G.R.A.S. AA0059

LEMO cable for low-noise system

   G.R.A.S. AA0035

BNC-BNC cable, 3 m


Optional items

For Ear Simulator Calibration

G.R.A.S. 42AP

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

G.R.A.S. 42AA

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

G.R.A.S. RA0090

94 dB Pistonphone Coupler



G.R.A.S. AA0046

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

G.R.A.S. AA0047

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

G.R.A.S. 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

G.R.A.S. KB0060

KEMAR Small Right Straight Pinna 55 Shore OO

G.R.A.S. KB0061

KEMAR Small Left Straight Pinna 55 Shore OO

G.R.A.S. KB0065

KEMAR Large Right Straight Pinna 55 Shore OO 

G.R.A.S. KB0066

KEMAR Large Left Straight Pinna 55 Shore OO

G.R.A.S. KB1060

KEMAR Small Right Straight Pinna, 35 Shore OO 

G.R.A.S. KB1061

KEMAR Small Left Straight Pinna 35 Shore OO

G.R.A.S. KB1065

KEMAR Large Right Straight Pinna 35 Shore OO 

G.R.A.S. KB1066

KEMAR Large Left Straight Pinna 35 Shore OO

G.R.A.S. KB0090

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

G.R.A.S. KB0091

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

G.R.A.S. KB1090

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

G.R.A.S. KB1091

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


Ear Mould Simulators

G.R.A.S. KB0110

Ear Mould Simulator for 2 mm inner diameter tubing 

G.R.A.S. KB0111

Ear Mould Simulator for 3 mm inner diameter tubing


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

G.R.A.S. RA0237

Straight Ear Canal Extension Kit for KEMAR 

G.R.A.S. RA0238

VA-tapered Ear Canal Extension Kit for KEMAR 

G.R.A.S. RA0239

Ear Canal Extension Kit w. silicone lining for KEMAR

G.R.A.S. RA0240

Holder for long 1/2" Microphone Kit for KEMAR 

G.R.A.S. RA0241

Holder for short 1/2" Microphone Kit for KEMAR

G.R.A.S. RA0243

Holder for 1/4" Microphone Kit for KEMAR

G.R.A.S. RA0244

O-ring kit for KEMAR, 2 pcs. 

G.R.A.S. RA0249 Straight Ear Canal Extension Kit for KEMAR,
made of POM, for binaural hearing aid test
G.R.A.S. RA0250 Tapered Ear Canal Extension Kit for KEMAR,
made of POM, for binaural hearing aid test


KEMAR Retrofit Kit for Binaural Hearing Aid Test

G.R.A.S. 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

G.R.A.S. KM0094

 PELI Case for KEMAR


Simulation Model of 45BB KEMAR

G.R.A.S. KB3000

Simulation Model of KEMAR with large pinnae

G.R.A.S. KB3001

Simulation Model of KEMAR with small pinnae


Stand for KEMAR

G.R.A.S. AL0026

 Loudspeaker Stand for KEMAR, Ø 35 mm



G.R.A.S. KB0000

KEMAR Handbook 

G.R.A.S. KB0010

T-Shirt for KEMAR 

G.R.A.S. Sound & Vibration reserves the right to change accessories without notice.