NumberLie: a game-based experiment to understand the acoustics of deception and truthfulness

To record clearly defined natural deceptive speech with precise knowledge of the ground truth and immediate consequences for the lying subject we present here the NumberLie game. The NumberLie design enables simultaneous and isolated audio recording of five players in our state-of-the-art laboratory, or adapted to any number of players in an online setting, playing against each other in a number-based game revolving around deception and trustworthiness. We describe the technical solutions employed to guarantee precise labelling of statements as truths or lies and immediate consequences to each interaction, backed by a performance-based financial reward to motivate participants. The design is easily manipulated to tailor to specific research questions, maintaining constant or eliminating completely additional sources of variability.