ISD-T360 ETC [List of Unclassifed Manufacturers], ISD-T360 Datasheet - Page 99

• Manufacturer Part Number: ISD-T360
• Description: VoiceDSP Digital Speech Processor with Master/Slave, Full-Duplex Speakerphone, Multiple Flash and ARAM/DRAM Support
• Manufacturer: ETC [List of Unclassifed Manufacturers]

ISD
40
43
45
35
Index
Acoustic Echo
Canceler (AEC):
SP_AEC_ENABLE
Acoustic Echo
Canceler (AEC):
SP_AEC_VOX_HYST
Acoustic Echo
Canceler (AEC):
SP_AEC_DTD_TH
Electric Echo Canceler
(EEC):
SP_EEC_LR_LEVEL
Parameter Name
Table 2-9: TUNABLE PARAMETERS: Speakerphone
Enables/disables the acoustic echo controller.
Legal values: 0 (disable), 1 (enable).
Controls the hysteresis in near-talker detection. (The
speakerphone state machine has a built-in hysteresis
mechanism to prevent fluctuations in the talker identification
process i.e., identifying the active side.) The value of this
parameter is a dimensionless number, which should be
evaluated during the tuning process for specific hardware.
Larger values for the parameter correspond to a wider
hysteresis loop. Negative values increase the probability that
the state machine remains in the last state.
Legal values: –127 to 127.
Controls the sensitivity of the system. Low values correspond to
high sensitivity, with a greater false alarm probability (i.e., an
echo is considered a real talker).
High values correspond to low sensitivity, with slower switching.
This parameter is affected by the loop gain and the specific
hardware characteristics.
Legal values: 0 to 127.
Controls the speakerphone gain from the line-in to the
speaker. The total attenuation, or gain, depends on both of
the analog gains and this value. The gain is:
where:
Legal values: 0 to 400.
K * signal
K = (SP_EEC_LR_LEVEL/4096) * (2
Description
(6 + VOL_LEVEL)/2
)
1
10
73
281
Default
2-59