There are several synonyms for the phrase "play back". One alternative is "replay", which means to repeat a recording or performance. Another choice is "rewind", which refers to the action of going back to an earlier section of a recording. "Review" is another synonym that means to examine or analyze a recording or performance. "Recap" is another option that indicates summarizing the main points of a recording or conversation. Finally, "resound" is also a possibility, meaning repeating a sound or voice. All of these synonyms describe the action of returning to or repeating an earlier recording or performance.