BRUEL & KJAER HATS 4606, Руководство пользователя

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High-frequency Head and Torso Simulator (HF HATS) Type 5128 – User Manual 24
Fig.3.5 Typical listener free-field frequency response curves (L and R) for High-frequency HATS (20 Hz – 20 kHz)
If measurements are to be made using both ears at the same time, then the matching between
the left and right ears of Type 5128 will be a combination of the tolerances on the pinnae (as given
in the specifications) and the tolerances on the ear simulators fitted. Mismatches can be
corrected for using the individual LFR measurements supplied on the data disk with Types 4620-R
and 4620-L, and the post-processing facilities of the audio analyzer being used.
The variation between any two left pinnae or any two right pinnae is less than 1 dB, so if
replacement pinnae are used there will be no problem comparing results with those of previous
measurements. For optimum accuracy the pinna marked with the serial number of Type 4620-R
(that is, that which is part of Type 5158) should be used, as it is with this pinna that the calibration
of Type 4620-R is made. The same applies to Type 4620-L.
3.3.2 Listener Diffuse-field Frequency Response
The listener diffuse-field frequency response (DFR), that is, the overall frequency response from
the undisturbed diffuse-field to the eardrum of the simulated listener, is shown in Fig.3.6. The
measurement is stored on the data disk in file DFR.
−20
−15
−10
−5
0
5
10
15
20
25
30
20 200 2000 20 000
Frequency (Hz)
180027
dB
LFR L and LFR R