TANDBERG D50104-15 用户手册

Health Care System III

67

Advanced Use

Select ‘On’ to allow automatic adjustments (Automatic Gain Control) of audio levels. When ‘On’, the AGC
maintains the audio signal level at a fixed value by attenuating strong signals and amplifying weak signals.
Very weak signals, i.e. noise alone, will not be amplified.

Example: In most conferences, the participants will speak at different levels, and be at different distances
from the microphones. As a result, some of the participants will be harder to hear than others. The AGC
corrects this problem by automatically increasing the microphone levels when “quiet” or “distant” people
speak, and by decreasing the microphone levels when “louder” people speak.

T

O

 

ENSURE

 

CORRECT

 

BEHAVIOUR

 

OF

 

THE

 AGC, 

IT

 

IS

 

CRUCIAL

 

THAT

 

THE

 

LEVELS

 

ON

 

THE

 

INPUT

 

CONNECTORS

 

ARE

 

ADJUSTED

 

CORRECTLY

USING

 

THE

 

AUDIO

 

INPUT

 

LEVEL

 

SETTINGS

. T

HE

 AGC 

WILL

 

NOT

 

COMPENSATE

 

FOR

 

SEVERE

 

MISADJUSTMENT

 

OF

 

INPUT

 

LEVELS

.

When applying a weak signal in the presence of strong background noise, the leveller might amplify the
background noise as well as the signal. Therefore, in noisy environments, it is advisable to turn the leveller
off.

This setting allows optimization of the echo canceller to the acoustic size of the room. Hard walls, many
windows etc. might require higher settings than expected. Carpets, curtains etc. might require lower settings.
Adjust the setting (NOTE: on the far end) if one of the following symptoms occur:

•

There is still some echo of your own audio. Increase the setting.

•

The system adapts slowly to acoustic changes in the room. Decrease the setting.

After a change, the system will need a few seconds to re-adjust.

If you experience echo caused by movements in the room, increase the value.