This directory contains drop-in voice announcements in raw format (no
.wav header):

bits/sample: 16
channels: 1
sample rate: 48 kHz
encoding: signed-integer, linear PCM
byte order: little endian

Each file contains an announcement to be played starting at 1 second
past the minute encoded in the file name. Eg, 0.raw is played during
minute 0 of each hour, and 30.raw is played during minute 30 of each
hour (this is the WWV station ID). When an announcement is played, it
pre-empts any tone that would otherwise be generated during that
minute.

If no file is found for a given minute, either silence or a tone will
be generated between seconds 1-45 depending on the default format for that
station. Files may not be more than 44 seconds long.

To save space, more than one minute label may link to a file. Eg, the
0.raw and 30.raw path names both link to the file wwv-id.raw.

File names not of the form #.raw or where # is a 1 or 2 digit decimal
number, are ignored.

