The aim of the study was to find ways to enhance earwitnesses’ memory for voices and content. Another aim was to evaluate an interview protocol used by the Swedish Security Service. Three different types of interviews were compared; the Cognitive Interview, the Swedish Security Service checklist, and a baseline interview. Both 11–13-year-olds (n = 119) and adults (n = 93) were exposed to an unfamiliar voice for 40 seconds and thereafter interviewed. Two weeks later, they were confronted with a seven voice line-up. The overall accuracy for correct identifications was 19.8%. No significant difference was found between the interview conditions. As for content, the results suggest that for adults, the Cognitive Interview may be beneficial for recall of a brief conversation. The checklist used by the Swedish Security Service did not have a positive effect on voice recognition, content recall or for descriptions of voices.