Toa N-8000 Series User Manual
Page 603
8-3
Chapter 8
APPENDIX
1.1.4. Full duplex conversation using echo canceller and voice switch
This is a speech method using the echo
canceller (see the previous page) in
combination with the voice switch. In
this method, the echo canceller works
continuously. Actions by way of the
voice switch overlap with those by way
of the echo canceller. The voice switch
works to reduce the other party's voice
level.
A strong action of the voice switch
makes the attenuation level large (when
its level is "0", only the echo canceller
works), while a weak action of the voice
switch makes the attenuation level
small.
The strength of voice switch action
depends on the total set value of the
microphone sensitivity and speaker
output volume at both stations.
As the value is small, the action of voice
switch becomes weak and as the value
is large, the action becomes strong.
Such operations allow the other party's
voice not to be cut, realizing nearly full
duplex conversation between stations.
However, depending on the settings
of microphone sensitivity and speaker
output volume, the other party's voice
may not almost be heard.
(Refer to
p. 8-5, "AEC + VS."
)
Full duplex conversation
Action of the
voice switch
(weak)
(Strong)
[When only the echo canceller works]
Notes
• The echo canceller works continuously.
• A smaller white arrow indicating the direction of
voice shows a smaller volume level of voice.
[When actions of the voice switch overlap]
Total set value of the
microphone sensitivity
and speaker output
volume at both stations
(small)
(Large)
[Setting example]
Setting at the station
• Microphone sensitivity: 1
• Speaker output volume: 3
Reduced by 4 dB
Setting at the station
• Microphone sensitivity: 1
• Speaker output volume: 5
Setting at the station
• Microphone sensitivity: 3
• Speaker output volume: 4
Reduced by 12 dB
(Example 1: When the total set value at both stations is “10.”)
(Example 2: When the total set value at both stations is “13.”)
Setting at the station
• Microphone sensitivity: 3
• Speaker output volume: 3