150 speakers x 26 letters of the English alphabet twice in random order. The data base comes with a technical report describing the data. CSLU has a telephone speech corpus of 1000 English alphabets.
Callers recite the alphabet with brief pauses between letters.
The data base is described in the proceedings of the International Conference on Spoken Language Processing. CSLU has released for universities its Continuous English Speech Corpus. The corpus contains recorded speech from 690 different speakers, with label files at various levels - including word level and phonetic labels. The data were collected as part of the OGI Multi-language telephone corpus. CSLU provides speech corpora to all universities without charge.