swirec_word_confidence_enabled

Controls whether Recognizer performs word confidence calculations.

Value

Boolean

Default

0 (disabled)

How to set

Shown in precedence order (see Rules of parameter precedence):

Set in the browser, using the Vendor-Specific-Parameters header in a RECOGNIZE or SET-PARAMS method.

In a parameter grammar.

In a grammar using a <meta> tag (see the text on recognition-time parameters in Parameters set in grammar files).

In Management Station set on the Nuance recognition service. If not using Management Station, set in a Recognizer configuration file (User-nrsxx.xml).

Usage

This is an advanced feature for use by developers who are familiar with word lattice recognition results (see Getting wordlattice recognition results).

Seldom used.

Performance

Enabling this feature increases CPU usage.

Applications can get word confidence scores as follows:

  • Set this parameter and add SWI_wordTimings to the swirec_extra_nbest_keys parameter. (Alternatively, you can add SWI_literalTimings instead.) Both keys include word confidence scores in the recognition result. The following example shows the confidence of a word appearing in the audio stream:
<seg0004>
   <type>word</type>
   <start>1560</start>
   <end>2090</end>
   <confidence>1.00</confidence>
   <literal>one</literal>
</seg0004>
  • Set this parameter and use the wordlattice media type to get raw recognition results. The XML result includes the scores in the <arc> element. For example:
    <arc type="silence" from="s0000" to="s0015" 
        acoustic_score="355.395" confidence="0.00099" />
  • Set this parameter and access word scores with ECMAScript code in speech grammars. For example, the code can set key/value pairs in the grammar to be returned to the application.

Browsers usually set this parameter in a RECOGNIZE request, and the parameter automatically reverts to the previous value after the recognition event. (Alternatively, browsers can use the SET-PARAMS method. See Configuring Recognizer with the browser.)

Vendor-Specific-Parameters: swirec_word_confidence_enabled=1

Sample definition in a grammar file, which is the most typical usage:

<meta name="swirec_word_confidence_enabled" content="1"/>