50 Hz & 60 Hz Mains Hum Attenuation in EEG Data (-75.5 dB)
Powerline noise (50 Hz in Europe/Asia, 60 Hz in North America) is the most pervasive technical artifact in electrophysiological recordings, often leaking into low-gamma neural frequencies (30–80 Hz).
The Danger of Standard FIR/IIR Notch Filters in Gamma Analysis
Crude notch filters introduce ringing artifacts, phase distortions, and broad attenuation pockets that eliminate legitimate 40 Hz gamma oscillations associated with cognitive control and pre-motor inhibition in Tourette research.
The Meridian Engine applies a zero-phase, high-Q notch filter paired with adaptive spectral subtraction. By calculating the exact local frequency drift and isolating the line harmonic, Meridian eliminates mains contamination without blunting neighboring cortical frequency bands.
Empirical Performance Specs
• Input: Synthetic 256 Hz EEG + 60 μV injected 50 Hz sinusoid
• Output Residual: < 0.01 μV RMS power at 50.0 Hz
• Attenuation Ratio: -75.5 dB
• Neighboring Band Distortion (48 Hz / 52 Hz): < 0.02% amplitude delta
Clean Your High-Noise Datasets
Whether your recordings suffer from poor grounding, shielded-room leaks, or line interference, Meridian removes the hum and provides verified spectral plots.
Submit Dataset for Line Noise Removal →