Register effects of imagined addressees on f0 across generations.

This study analyzed fundamental frequency (f0) data from 717 German speakers, collected via the Plapper smartphone app, to investigate phonetic variation as a function of imagined addressee authority. Participants justified crossing a street during a red light, addressing either an imagined friend (male or female) or an imagined male police officer. Speakers consistently produced higher f0 when addressing the police officer, regardless of sex or age. The findings support Bell's Audience Design model, which posits that speakers adapt their speech to gain approval, and Ohala's frequency code theory, which associates elevated f0 with submissiveness in interactions involving authorities.