User Manual

Chapter 6 Component Guide
DME Designer Owner’s Manual
483
MY4-AEC Signal Flow
The local and remote locations in a teleconferencing system are referred to as the “near end” and “far
end”, respectively. The MY4-AEC acoustic echo canceller (AEC) works by comparing the reference
signal received from the far-end with the signal from the microphone in order to determine which
components of the signal are echo, and then subtracts only the far-end echo component from
microphone signal. The near-end sound is thus clearly transmitted to the far end without echo
 NR (Noise Reduction)
Automatically detects and reduces constant environmental noises such as projector fans or air
conditioning.
 FBS (Feedback Suppressor)
Automatically detects the frequencies at which feedback is occurring and applies notch filters at those
frequencies to stop the feedback. 42 notch filters are available for each AEC channel. The notch filters
are reset (i.e. returned to “not applied” status) when the DME64N/24N power is turned off.
Reference signal FBS: Feedback suppressor NR: Noise reduction
From Far
-
end A Far
-
end Voice A
NR
From Far
-
end B Far
-
end Voice B
NR
From Far
-
end C Far
-
end Voice C
NR
From Far
-
end D Far
-
end Voice D
NR
To Far
-
end 4
Near
-
end Mic. 4
Near
-
end Voice 4
NR
FBS
To Far
-
end 3
Near
-
end Mic. 3
Near
-
end Voice 3
NR
FBS
To Far
-
end 2
Near
-
end Mic. 2
Near
-
end Voice 2
NR
FBS
To Far
-
end 1
Near
-
end Mic. 1
Near
-
end Voice 1
NR
FBS
AEC
AEC
AEC
AEC
Matrix Router