Synchronization has recently received attention as a form of interpersonal interaction that may affect the affiliative relationships of those engaged in it. While there is evidence to suggest that synchronized movements lead to increased affiliative behavior (Hove & Risen, 2009; Valdesolo & DeSteno, 2011; Wiltermuth & Heath, 2009), the influence of other interpersonal cues has yet to be fully controlled. The current study controls for these features by using computer algorithms to replace human partners. By removing genuine interpersonal interaction, it also tests whether sounds alone can influence affiliative relationships, when it appears that another human agent has triggered those sounds. Results suggest that subjective experience of synchrony had a positive effect on a measure of trust, but task success was a similarly good predictor. An objective measure of synchrony was only related to trust in conditions where participants were instructed to move at the same time as stimuli.