If you need someone to sound like they’re on the other side of a telephone call in a video or film, here’s a quick tutorial on how to apply that effect to a voice or dialogue audio track. We run through how to do this in Premiere Pro, Audition, and Audacity.
The main idea is to cut all of the low frequency and high frequency sound leaving a very mid-focused sound. This is exactly what old-school phones did. So that just requires a very simple EQ plugin and a quick edit. You could even save a preset for your EQ plugin if you need to do it frequently.