A NYNEX network service, VOIS, automates the processing of intercept calls. VOIS employs speech recognition when customers are asked to say the dialed number. Some responses have been recorded in an application-specific database, VOIS-2, which contains information on recognizer and system performance and customer behavior. VOIS-2 has 1636 utterances of which 54% are continuously spoken digit strings with no extraneous speech, 14% have extraneous speech, and 32% have no speech at all. For the 881 in-vocabulary utterances, the string accuracy is 49% and the single-digit accuracy 85%. The VOIS application accepts only seven-digit strings, with a recognition confidence level above a predetermined threshold, and with a valid initial three-digit end-office code. For the 282 utterances that meet these stringent criteria, the string accuracy is 91. 5% and the single-digit accuracy 98. 5%. Keywords: Automatic Speech Recognition, Digit Recognition, NYNEX Science and Technology, Operator Number Identification, Operator Services, VOIS
Bibliographic reference. Yashchin, Dina / Ortel, William C. G. (1991): "Experience with speech recognition in automating telephone operator functions", In EUROSPEECH-1991, 727-730.