Speech Technology Center ANF II, Руководство по эксплуатации

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APPENDIX
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APPENDIX D
RECORDING RECOMMENDATIONS
To receive high-quality audio records, we recommend following these rules:
1. Use the stereophonic recording mode without the compression with the 44,1kHz sample rate.
2. Usage of monophonic recording mode allows to record longer files on the same hard disk space.
3. Use manual adjustment of the input signal level.
4. To avoid the loss of useful information, we recommend using voice activation only if the level of a signal is stable and
predictable enough. It is hard to use audio files recorded in voice activation mode as an exhibit because it is hard to prove
their authenticity.
5. During the recording, place microphones as close as it possible to the speech signal source, and as far as it possible from
sources of acoustic and electromagnetic interferences. The closer microphones to the speech signal source, the higher SNR
ratio, the lesser negative influence of the reverberation and the higher speech intelligibility.
6. External microphones are more sensitive and it is easy to fix them on clothes (on the jacket’s lapel or shirt’s collar). They are
more vulnerable to electromagnetic interferences. We recommend placing external microphones at the 15 cm (5, 91 inches)
distance minimum from each other.
7. Place external microphones in a way to avoid the influence of vibration, shock loads, and friction between the device and
other objects (for example, clothes) especially during the movement.
8. Avoid direct contact of the device or external microphones with rigid or metal surfaces (for example, table tops, car bodies,
concrete walls).
9. If you perform the monophonic recording, only the signal, which is coming through the input of one microphone (left one)
will be recorded.
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