gqrx-ghostbox

gqrx-ghostbox is a Python script by Doug Haber that communicates with a running GQRX instance via its built-in TCP remote control API. The script commands GQRX to step through a frequency range at configurable intervals, producing a ghost box effect using the RTL-SDR hardware and GQRX's audio output. All parameters — frequency range, step size, dwell time — are set in the script or as command-line arguments, making every sweep session fully documented and reproducible.

The key advantage is complete transparency and open inspection. The entire sweep algorithm is visible in the Python source code — there is nothing proprietary or unknown about how the audio is generated. This matters for methodological honesty: when publishing or sharing ITC investigation results, being able to point to the exact algorithm and parameters used is important for peer review.

For investigators interested in studying ITC as a psychological or perceptual phenomenon, gqrx-ghostbox on a Mac is an excellent research platform. You can modify the dwell time formula, implement random vs sequential stepping, or add frequency weighting to test whether sweep parameters affect the perceived 'voice density' of the output. The script can log all frequency positions to a file for correlation with event timestamps.