Both of my conversations took place on the premises of Deli Zone, Denver's home for legendary New-York subs; however, the roles I assumed in each differ greatly.  In one, I was speaking to a customer, taking his order, exchanging pleasantries;  In the other, I was on a break, shooting-the-proverbial-shit with a coworker.  I could tell, without even consulting the numbers, I equipped a lower pitch when talking to the customers than when I spoke to by buddy.  In fact, the average pitches differed by nearly two and one half levels.  It was hard to get levels on the customer's voice, considering my placement-of-my-recording-device-close-enough-to-capture-the-exchange-yet-hidden-enough-to-avoid-detection-by-the-hands-of-my-ignorant-customer, but my coworker, during our conversation used a voice with pitch levels analogous to mine (he was also singing-at-times, which reflected in the data).  Perhaps we were mimicking each other with our higher pitches–I do not know who began the trend.  Also worth noting, the conversation was composed of many questions, explanations, and realizations, which lend to higher pitch levels.  I think the loudness numbers are somewhat unreliable, considering the unequal proximity of the microphone to each of the speakers sound-hole.  I was trying to seem trustworthy to the customer by using a "stronger" (deeper) voice.  I had no need to prove anything to my comrade, so I used a more comfortable, natural, open voice.