An Infrasonic Missing Fundamental Rises at 18.5Hz

Abstract

The Missing Fundamental (MF) phenomenon is an auditory processing artifact which arises from the perception of a harmonically-structured complex sound in the absence of the complex sound’s fundamental frequency (f₀). Constructive interference occurring between constituent waveforms of the harmonic series may elicit a perceptible tone at the f₀’s pitch. A related illusion, known as binaural auditory beats (BAB), may also generate nonexistent perceptible pitches through a shared mechanism. A harmonic series suggesting to an infrasonic f₀ (1/f) noise and broken MF conditions. This data suggests that an infrasonic MF tone is generated, despite the normally imperceptible nature of the sound. The computational phenomenon reported here may also occur throughout the cortex, where it could influence or induce different conscious states. The practical implications of altering cortical activity is relevant in understanding processing disorders such as Attention Deficit Hyperactivity Disorder and Schizophrenia.