Time-Frequency Displays

International Standard Book Number — Click for https://mathworld.wolfram.com/ISBN.html

Loudness is a quantity, expressed in sones, which corresponds to the perceptual intensity of a sound. — Click for http://www.acoustics.salford.ac.uk/research/arc/cox/sound_quality/loudness.htm

Psychoacoustics is the science of the human perception of sound. — Click for http://en.wikipedia.org/wiki/Psychoacoustics

Click for https://ccrma.stanford.edu/~jos/mdft/Decibels.html

A signal is typically a real-valued function of time. A discrete-time signal is typically a real-valued function of discrete time, and is therefore a time-ordered sequence of real numbers. — Click for http://ccrma.stanford.edu/~jos/filters/Definition_Signal.html

The spectrogram is a three-dimensional plot of signal amplitude versus time and frequency. It is typically computed using the Short Time Fast Fourier Transform (STFT). — Click for http://en.wikipedia.org/wiki/Spectrogram

The Short Time Fourier Transform (STFT) computes the spectrum (DFT) of successive time frames of a signal. — Click for https://ccrma.stanford.edu/~jos/sasp/Short_Time_Fourier_Transform.html

Spectrum analysis of sound is analogous to decomposing white light into its component colors by means of a prism — Click for https://ccrma.stanford.edu/~jos/mdft/Example_Applications_DFT.html

Noise (in signal processing) is a random signal. In the language of statistical signal processing, a noise signal is typically modeled as 'stochastic process', which is in turn defined as a sequence of random variables. — Click for https://ccrma.stanford.edu/~jos/sasp/What_Noise.html

A sinusoid is any function of the form A sin(ω t+φ), where t is the independent variable, and A, ω, φ are fixed parameters of the sinusoid called the amplitude, (radian) frequency, and phase, respectively. Sinusoidal motion is produced by any 'pure' vibration, such as that of an ideal tuning fork or mass-spring system. — Click for https://ccrma.stanford.edu/~jos/mdft/Sinusoids.html

Time-Frequency Displays

The preceding chapters have been concerned with the spectrum analysis of sinusoids and noise at a particular point in time (or a single spectrum for all time). This chapter introduces the Short-Time Fourier Transform (STFT)--a time-ordered sequence of spectral estimates, each using a finite-length analysis window. The STFT is used to compute the classic spectrogram, used extensively for speech and audio signals in general [132,57,199,162,226,74,81]. Finally, we point to methods for making spectrograms correspond better to audio perception, so that what you see is what you hear, to a greater extent. In particular, a loudness spectrogram based on a psychoacoustic model of time-varying loudness perception is described.

Time-Frequency Displays

``Spectral Audio Signal Processing'', by Julius O. Smith III, W3K Publishing, 2011, ISBN 978-0-9745607-3-1. Copyright © 2022-02-28 by Julius O. Smith III Center for Computer Research in Music and Acoustics (CCRMA), Stanford University

``Spectral Audio Signal Processing'', by Julius O. Smith III, W3K Publishing, 2011, ISBN 978-0-9745607-3-1.
Copyright © 2022-02-28 by Julius O. Smith III
Center for Computer Research in Music and Acoustics (CCRMA), Stanford University