HomeTroller-SE Getting Started Guide – rev 3.0 10/12/2011
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expression results in grammar that supports “try this”, “please try this”, and “please please try
this”, with unlimited iterations of “please”:
please* try this
The following grammar format excludes “try this” (spoken by itself) because the + operator
defines at least one instance of “please”. So, the only allowable phrases are “please try this” or
“please please try this”:
try this
The repetition operators follow normal rules of precedence and apply to the immediately
preceding text item. For example, the following grammar results in “New York” and “New York
York”, but not “New York New York”:
New York+
Therefore, you typically want to use these operators with the grouping characters. For example,
the following grammar includes both “New York” and “New York New York”:
(New York)+
Repetition operators are useful when you want to compose an expression that includes a
repeated sequence such as a phone number or specification of a list of items:
call (one|two|three|four|five|six|seven|eight|nine|zero|oh)*
Id like (cheese|pepperoni|pineapple|canadian bacon|mushrooms|and)+
Although the operators can also be used with the optional square brackets grouping character,
doing so may reduce the efficiency of the Speaker Client as it processes the grammar.
Word Spotting
You can also use ellipses (…) to support word spotting. Word spotting is where you tell the
speech recognition engine to ignore words spoken in this position in the phrase (sometimes
called garbage words). When you use ellipses, the speech engine recognizes only specific words
in the string regardless of whether they‟re spoken with adjacent words or phrases. For example,
if you set this property to “[…] check mail […]”, the speech recognition engine will match
phrases like “please check mail” or “check mail please” to this command. Ellipses can be used
anywhere within a string.
Be careful when using this technique as voice settings with ellipses may increase the potential of
unwanted matches.
Tips and Suggestions
When defining the expression for your command, include at least one word that is
required; that is, avoid supplying only optional words.
Make sure that the word includes only pronounceable words and letters. For numbers, it
is better to spell out the word than use an ambiguous representation. For example, “345”
is not a good grammar form. Similarly, instead of “IEEE”, use “I triple E”.
