Method for recognizing alphanumeric strings spoken over a telephone network

Abstract

The present invention describes a method for recognizing alphanumeric strings spoken over a telephone network (10) wherein individual character recognition need not to be uniformly high in order to achieve high string recognition accuracy. Preferably, the method uses a processing system (14) having a digital processor, an interface (42) to the telephone network (10), and a database (32) for storing a predetermined set of reference alphanumeric strings. In operation, the system (10) prompts the caller to speak the characters of a string, and characters are recognized using a speaker-independent voice recognition algorithm (48). The method calculates recognition distances between each spoken input character and the corresponding letter or digit in the same position within each reference alphanumeric string. After each character is spoken (206), captured and analyzed (208), each reference string distance is incremented (204) and the process is continued, accumulating distances for each reference string, until the last character is spoken. The reference string with the lowest cumulative distance is then declared to be the recognized string (210).