“To arrive at those state-by-state breakdowns, the analytics firm Marchex used what it calls Call DNA technology—software that analyzes call recordings to determine things like rate of speech, density of speech, hold times, and silences—on a set of calls recorded between 2013 and 2015. (These are the recordings that result when a pleasant robo-voice informs you that “this call may be recorded.” Marchex’s analysis includes more than 4 million such calls.)”