Properties in MRCP/VXML/API

One difficult thing about developing applications using standards such as MRCP and VXML is that the names of similar parameters are often slightly different between the standards. This is particularly important when tuning voice activity detection parameters.

The following table presents a comparison of VAD properties in MRCP and their equivalent name in VXML and the LumenVox API (used with LV_SRE_StreamSetParameter and LVSpeechPort::StreamSetParameter).

In some cases the parameters do not have direct matches, so the exact mappings may differ depending on how a platform interprets the meaning of one specification or the other. Thus you should consider this table an informational guide rather than as an official interpretation of the standards.

MRCP VXML API
sensitivity-level sensitivity STREAM_PARM_VAD_VOLUME_SENSITIVITY
speech-complete-timeout completetimeout STREAM_PARM_VAD_EOS_DELAY
speech-incomplete-timeout incompletetimeout Not supported by LumenVox
com.lumenvox.end-of-speech-timeout N/A STREAM_PARM_END_OF_SPEECH_TIMEOUT
no-input-timeout timeout STREAM_PARM_BARGE_IN_TIMEOUT
confidence-threshold confidencelevel N/A (handled by application)
speed-vs-accuracy speedvsaccuracy PROP_EX_SPEED_VS_ACCURACY
n-best-list-length maxnbest PROP_EX_MAX_NBEST_RETURNED
recognition-timeout maxspeechtimeout N/A
waveform-url N/A N/A
dtmf-interdigit-timeout interdigittimeout N/A
dtmf-term-timeout termtimeout N/A
dtmf-term-char termchar N/A

Note that the sensitivity-level (sensitivity in VXML) works different with MRCP/VXML than in our API. In our API, setting this value higher makes it less sensitive to barge-in. MRCP and VXML are the opposite.

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