PhoneBook: NYNEX Isolated Words

PhoneBook is a phonetically-rich, isolated-word, telephone-speech database, created because of (1) the lack of available large-vocabulary isolated-word data, (2) anticipated continued importance of isolated-word and keyword-spotting technology to speech-recognition-based applications over the telephone and (3) findings that continuous-speech training data is inferior to isolated-word training for isolated-word recognition. <p> The goal of PhoneBook is to serve as a large database of American English word utterances incorporating all phonemes in as many segmental/stress contexts as are likely to produce coarticulatory variations, while also spanning a variety of talkers and telephone transmission characteristics. We anticipate that it will be useful in ways analogous to TIMIT/NTIMIT. </p><p> The core section of PhoneBook consists of a total of 93,667 isolated-word utterances, totalling 23 hours of speech. This breaks down to 7,979 distinct words, each said by an average of 11.7 talkers, with 1,358 talkers each saying up to 75 words. All data were collected in 8-bit mu-law digital form directly from a T1 telephone line. Talkers were adult native speakers of American English chosen to be demographically representative of the U.S. </p><p> Given the large set of talkers being recruited for PhoneBook database, it made sense to exploit the opportunity to collect additional utterances. We have chosen spontaneous numerical utterances, because of widespread interest in them and the need for very large numbers of talkers for research into spontaneous-speech effects. We restricted to just three spontaneous digit sequences and one money amount, as the lists for the core of PhoneBook have been designed to approach the limit of reasonable duration for a caller's session. As a result, PhoneBook contains a total of 5,105 spontaneous utterances. </p></br>