Lost audio stimuli from psycdat file

Apologies if this is the wrong place to post, but not sure where else to go!

We are conducting a study where participants hear audio stimuli (a name) and then select the image that best suits the name. We have run into an issue where the name stimuli was not being recorded in the data for about 20 participants. We have updated the code for subsequent studies to record the name stimuli, but is there any way to obtain this lost data? We want to know which names/audio files were being presented.

Thank you for your help!!