After submitting a voice job, you can determine the results of a specific destination by reading the JobDeliveryStatusResult. One element that is particularly interesting is the BaudRate. For voice jobs, this element does not contain the baud rate, but rather the call status code specified in the attached table.
You will also see a sample xml file showing the position of the BaudRate element.

Attachment	Size
Voice Job Baud Rate Status.doc	45 KB