The waveforms are SPHERE-headered, digitised, zero-meaned (using NIST's bias), and compressed (using NIST's transparent shorten algorithm w_encode).
The filename extension for the waveforms will contain the characters, ``wv'', followed by a 1-character code to identify the channel. The 1024-byte NIST header for each waveform contains the following fields/types:
Field Type Description - Probable defaults marked ()
speaker_id string 3-char. speaker ID from filename
speaking_mode string speaking mode ("read-common",
"read-adaptation")
recording_site string recording site
recording_date string beginning of recording date stamp of the
form DD-MMM-YYYY.
recording_time -s11 string beginning of recording time stamp of the
form HH:MM:SS.HH.
recording_environment string text description of recording environment
microphone string microphone description
utterance_id string utterance ID from filename of the form
SSSTEEUU as described in the filenames
section above.
prompt_id string WSJ source sentence text ID - see .ptx
description below for format
database_id string database (corpus) identifier
database_version string database (corpus) revision ("1.0")
channel_count integer number of channels in waveform ("1")
speaker_session_number string 2-char. base-36 session ID from filename
sample_count integer number of samples in waveform
sample_max integer maximum sample value in waveform
sample_min integer minimum sample value in waveform
sample_rate integer waveform sampling rate ("16000")
sample_n_bytes integer number of bytes per sample ("2")
sample_byte_format string byte order (MSB/LSB -> "10",
LSB/MSB -> "01")
sample_coding string waveform encoding
sample_checksum integer checksum obtained by the addition of all
(uncompressed) samples into an unsigned
16-bit (short) and discarding overflow.
sample_sig_bits integer number of significant bits in each sample
("16")
session_utterance_number string 2-char. base-36 utterance number within
session from the filename
end_head none end of header identifier