Data quality and trust in the data collection process are critical concerns in survey research, particularly when surveyors are needed for reaching “diverse and inconvenient subject pools.” In response to irregularities in a smartphone-based pilot survey data collection in Nigeria, we developed an audio check method that unobtrusively recorded surveyors reading aloud questions to participants. We present evidence that this method detected wholesale data fabrication in 14% of our surveys, prevented further fabrication, and improved data quality through provision of regular feedback to surveyors. Using simulation, we demonstrate that undetected fabrication would have introduced significant bias in our analyses. The audio check performs well compared to more traditional methods of detecting fabrication, and a comparative cost–benefit analysis reveals a savings of more than US $1,500 per surveyor by relying on the audio check. The audio check is a viable tool for psychologists who work with survey teams.