dtmf recognition accuracy with *, #, and digits

[prairieblue]

I would like to recognize commands of up to 3 keystrokes, with the possiblility of the first two commands as *.

I am using the following grammar:
<grammar type="application/x-jsgf" mode="dtmf">
["*"]["*"](1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0 | "#")
</grammar>

The * commands are seldom recognized.

I swapped the role of the * key with 1 as follows:
<grammar type="application/x-jsgf" mode="dtmf">
[1][1]("*" | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0 | "#")
</grammar>

This is very accurate and never misses. Do you have any suggestions to improve the performance of the first case?

Is it possible to allow bargein only with dtmf tones and to ignore all extraneous noise?

[support]

My approach to your IVR input requirement is slightly different. I think I would do the following:

Code: Select all

<!-- RESTRICT INPUT TO DTMF ONLY -->
<property name="inputmodes" value="dtmf"/>
<field name="testme">
<prompt>Enter exactly 3 digits. You can use the star key to replace the first two digits</prompt>
<grammar type="application/x-jsgf" mode="dtmf">
<!-- LIKE IN REGEXPS, THE ^ REPRESENTS THE STRING START -->
^
("*"|1|2|3|4|5|6|7|8|9|0)
("*"|1|2|3|4|5|6|7|8|9|0)
(1|2|3|4|5|6|7|8|9|0)
<!-- LIKE IN REGEXPS, THE $ REPRESENTS THE STRING END -->
$
</grammar>
<filled>
You entered <value expr="testme"/>
</filled>
</field>

While somewhat verbose, this will, first, ensure that three and only three DTMF inputs will be permitted as a match for the IVR grammar, and b) should eliminate any ambiguity that might have been introduced with the use of the optional item (the "[" and "]") construct.

I'll check in with engineering as to why your <grammar> didn't match on the stars. I tried it on a test account and it seemed okay upon cursory inspection, but we'll certainly double check the IVR issue.