|The NTIMIT corpus was developed by the NYNEX Science and Technology Speech Communication Group to provide a telephone bandwidth adjunct to TIMIT.|
NTIMIT was collected by transmitting all 6,300 original TIMIT recordings through a telephone handset and over various channels in the NYNEX telephone network and redigitizing them. The recordings were transmitted through ten Local Access and Transport Areas, half of which required the use of long-distance carriers.
In order to calibrate the transmission characteristics of the various channels, stationary 1 kHz and frequency-sweeping tones were also recorded for each of the transmission channels. These are found on Disc 2.
The re-recorded waveforms were time-aligned with the original TIMIT waveforms so that the TIMIT time-aligned transcriptions can be used with the NTIMIT corpus as well. In additiont to the documentation on the disc, see Jankowski et al., "NTIMIT: A Phonetically Balanced, Continuous Speech, Telephone Bandwidth Speech Database," Proc. ICASSP-90, April 1990. NYNEX retains full copyright on the corpus and all associated materials.