In order to *"...automatically reference each frame to start time of the file..."* you have to know the start time of that file (well, duh!). Fortunately, sound files commonly include that information as part of their filename. For example, I was recently asked to analyze a sound file with the following filename: SWIFT #2_96K_**20200621_172433**.wav Note the bolded portion, which contains the **date_time** that the recording started. This recording started on June 21, 2020 at 24 minutes and 33 seconds after 5 pm. The field recorder automatically appended that information to the filename as **yyyymmdd_hhmmss**, where: **yyyy** = year<br> **mm** = month<br> **dd** = day<br> **hh** = hour (24)<br> **mm** = minutes<br> **ss** = seconds If this file contained a sound that had a start time of 14 seconds, then that time is simply added to the filename's **date_time**. In this case that sound would have started on June 21, 2020 at 24 minutes and 47 seconds after 5 pm. AFAIK, most field recorders automatically include the starting **date_time** as part of the filename. If your sound files do not include this, then you'll need to locate some metadata that includes the recording's start time. Failing that, I don't know how you would be able to determine a start time...