Directory assistance by means of automatic recognition of spoken spelled names

An automatic word recognizer is used to accept strings of spelled letters spoken in isolation. The output of the recognizer is a set of best candidate letters for each letter spoken in the string. Candidate strings forming spelled last names and initials are compared to name strings obtained from a telephone directory stored in a disk file. A systematic search is carried out to find a matching entry in the directory. An evaluation has been carried out with ten talkers spelling lists of names extracted from an 18,000 entry telephone directory. Although the median acoustic error rate per spelled letter is approximately 20%, the median error rate in furnishing the requested directory entry is approximately 4%.