2018-07-02 15:07:00 UTC
The NAS panel created spectograms of the "hold everything secure until
homicide and other investigator can get there" for both Channel 1 and
Channel 2. They found that they had to compress the Channel 2 spectogram
by a factor of .91 to obtain the best correlation with the same phrase
on Channel 2.
See the caption for Figure B-6 at the following link (That would be page
107 of the report)