Wolfgang Buescher (DL4YHF)
Highly configurable real-time spectrum analyser used in amateur radio, acoustic research, and paranormal audio investigation. Displays live audio as a scrolling spectrogram — used by researchers monitoring for infrasound and sub-audio anomalies.
Spectrum Lab is a free Windows DSP tool from German amateur radio operator Wolfgang Buescher. Originally designed for amateur radio signal analysis, it has been adopted by paranormal investigators for real-time frequency monitoring. Unlike Audacity's post-hoc analysis, Spectrum Lab runs continuously in real time, displaying incoming audio as a scrolling spectrogram — letting an investigator literally watch the frequency content of a room change over time.
You can set threshold alerts — if signal power in a specific frequency band exceeds a defined level, Spectrum Lab can log the event, trigger a recording, or send a command. This makes it useful for unattended monitoring of environments where you want to capture anomalous acoustic events automatically without recording a continuous 8-hour audio stream.
Spectrum Lab's waterfall display can be configured to show very long time windows — hours of data on a single screen. This is valuable for identifying cyclical patterns (HVAC cycles, traffic, building settling) versus anomalous one-off events. The software supports infrasound analysis down to 0.01Hz if paired with appropriate low-frequency microphones, making it useful for researchers investigating the 18.98Hz resonant-frequency hypothesis.
Investigator Note
Validate your setup against a known audio source (tone generator at known frequency) before deploying for investigative monitoring. The software's low-frequency capabilities require appropriate hardware — a standard laptop microphone will not capture infrasound.
Queen Mary University of London
Advanced spectrographic analysis tool from Queen Mary University. Designed for music research but adopted by EVP investigators for its annotation layers, pitch tracking, and publication-quality spectrogram output.
John Mulcahy
Professional room acoustic measurement suite. Used by paranormal investigators to establish acoustic baselines before investigations — characterising room resonances, standing waves, and noise floor so anomalies can be distinguished from environmental artifacts.
Cornell Lab of Ornithology
Scientific bioacoustics analysis suite from Cornell Lab. The tool of choice for academic-level EVP and acoustic anomaly analysis. Provides publication-quality spectrographic analysis with measurement statistics, selection tables, and peer-review-ready output.
