This directory contains the Census (AN4) database audio files. Some
files from the original database were excluded, namely those
with filenames starting with "cen9".

The AN4 database was recorded at Carnegie Mellon University circa
1991. For more detailes, please see "Acoustical and environmental
robustness in automatic speech recognition", by Alex Acero, published
by Kluwer Academic Publishers, 1993.

The files are in NIST's Sphere format, where files have a 1024-byte 
header describing the data format.

The directories contain:

-wav/an4_clstk: training data set recorded on close talking microphone.

-wav/an4test_clstk: test data set recorded on close talking microphone.

-etc: directory containing the transcriptions, control files, dictionary etc.