References: Microphone Input & FFT Spectral Analysis¶
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Fast Fourier transform - Wikipedia - Mathematical algorithm that computes the Discrete Fourier Transform (DFT) of a sequence, converting time-domain waveform signals into frequency-domain spectral amplitudes.
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Spectrogram - Wikipedia - Visual representation of the spectrum of frequencies in a signal as it varies with time. Fundamental for designing audio-reactive visualizers and music analyzers in multimedia projects.
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Audio frequency - Wikipedia - The audible frequency range (20 Hz to 20,000 Hz), octave bands, and frequency divisions (sub-bass, bass, midrange, presence, brilliance) utilized in audio engineering and visual analysis.
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Elements of Computer Music - F. Richard Moore - Prentice Hall - Moore provided the classic, rigorous mathematical derivation of digital Fourier analysis and spectral decomposition tailored specifically for musicians and computer scientists working in acoustic software.
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Audio-Vision: Sound on Screen - Michel Chion - Columbia University Press - Chion established the theoretical framework of synchresis—the spontaneous forging of perceptual links between visual motion and auditory events in audiovisual media and interactive installations.
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p5.FFT and p5.AudioIn Reference - p5.js Foundation - API reference for live microphone input (p5.AudioIn), spectral analysis (p5.FFT), analyze(), waveform(), getEnergy('bass', 'treble'), and smoothing settings for reactive graphics.
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Visualizing Audio with the Web Audio API - MDN Web Docs - Comprehensive guide on using AnalyserNode, frequency bin counts, byte frequency arrays, and canvas rendering for real-time oscilloscopes and frequency bars in web applications.
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The Coding Train: Frequency Analysis with FFT in p5.js - The Coding Train - Visual video lesson demonstrating how to map FFT frequency spectrum arrays to radial circular visualizers and detect rhythmic drum beats in code with p5.js audio tools.
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3Blue1Brown: But what is the Fourier Transform? - 3Blue1Brown - Renowned visual mathematics video lesson explaining how unwrapping wave frequencies on complex circles separates composite audio signals into constituent pure tones with visual clarity.
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HTML5 Rocks: Exploring the Web Audio AnalyserNode - web.dev / Google - Technical guide explaining decibel scale normalization, time-domain smoothing constants, and audio input permission handling in modern browsers for music visualization.