iZotope RX

iZotope RX is the professional standard in audio restoration, used in film post-production, forensic audio analysis, and broadcast. For paranormal investigators, its Spectral Repair module is the most important feature: it can surgically remove specific frequencies from specific time regions, eliminating investigator coughs, footsteps, electrical hum, and radio interference while leaving the rest of the audio completely intact.

The Dialogue Isolation module (RX 9+) uses AI to separate speech from background noise — originally designed for film ADR work, it can separate a spoken anomaly from wind noise, rain, or HVAC with remarkable precision. Unlike Audacity's blunt noise reduction (which applies to the entire file), RX's tools operate at the spectral level, preserving audio integrity outside the targeted region.

RX Elements ($99) provides Spectral Repair and noise reduction at a lower entry point. The full Standard edition adds Dialogue Isolation and batch processing. Many professional audio forensic labs use RX as their primary evidence processing tool. Any processing applied to EVP evidence must be documented — processed files should never replace originals.