BRUEL & KJAER 2209 - Artificial Mastoid 4930

Fig.6.28. Artificial Ear Type 4152
Fig.6.29.
Artificial Ear Type 4153
6.2.14. Artificial Mastoid 4930
The Artificial Mastoid Type 4930 was developed as an objective means of
calibrating bone vibrators of the type used in bone conduction hearing aids.
It consists basically of an inertial mass of 3.5 kg, which approximates the
mass of an average human head, into which a smaller mass is set.
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