Explanation of the audit information provided in "callinfo.tbl"

The file "callinfo.tbl" contains the information produced by manual
auditing of the CallHome Mandarin conversations.  The auditing process
was set up to accomplish two things: (a) provide information about the
speakers and channel quality for the conversation, and (b) establish
the region of the conversation to be used for transcription.

The table file contains multiple lines for each conversation, to
provide the following information:

 - total number of speakers and total number of females and males
 - channel quality for each side of the conversation (see below)
 - number of speakers per channel and number of males/females per channel
 - gender, approximate age, and other features of each speaker

Each line begins with the first two letter of the language followed by
the four-digit conversation number.  Here is a sample set of lines for
one of the conversations:

ma_0003 ntalkers=2 nfemale=1 nmale=1
ma_0003 siA ntalkers=1 nfemale=1 nmale=0
ma_0003 siA difficulty=2 bg_noise=1 chan_noise=2 distortion=2 crosstalk=1
ma_0003 siA comment 5 min. : 37.04 to 337.56 sec.  This whole file is from 24 to 362 sec.
ma_0003 siB ntalkers=1 nfemale=0 nmale=1
ma_0003 siB difficulty=3 bg_noise=4 chan_noise=3 distortion=3 crosstalk=2
ma_0003 taA sex=female age=adult rate=normal artic=clear accent="Putonghua (southern)" acc_pron=1 dial_wds=2
ma_0003 taB sex=male age=adult rate=normal artic=clear accent="Putonghua (southern)" acc_pron=2 dial_wds=1

The first line gives the total number of speakers in the transcribed
portion of the conversation.  The next four lines indicate the channel
quality and the number of speakers on a per-channel basis.  The
remaining lines provide information on each of the speakers
(typically, there are only two speakers in the conversation - one per
channel - so there would be only two lines in this portion of the
table).

The information on channel quality should be interpreted as follows:

 - Difficulty refers to the overall quality of the channel in terms of
number of speakers, background noise, channel noise, speed, accent,
articulation, etc.

 - Background noise refers to the amount of sounds not made by the
speakers, e.g., baby crying, television, radio, etc.

 - Channel noise refers to static or channel break-up.
 
 - Distortion refers to echo and other types of recording problems.

 - Crosstalk refers to audibility of the channel A speaker on channel
B, and vice-versa (i.e. due to the echo in the telephone circuit)

All attributes are rated on a scale of 1 to 5, where 1 always refers
to optimal channel conditions and 5 refers to the least optimal, but
still usable channel conditions.