Chapter 1 - Introduction - The relevance of studying the properties of signals and systems for work in the speech and hearing sciences; examples of signals and systems; input and output signals.
Chapter 2 - Signals in the real world - the similarity of acoustic, mechanical and electrical signals; transduction.
Chapter 3 - Introduction to signals - The specification and construction of sinusoids; the concepts of frequency, period, amplitude and phase; periodic and aperiodic sounds; measures of amplitude - peak- to-peak, rms; dB scales.
Chapter 4 - Introduction to systems - Linearity, additivity, homogeneity and time-invariance. Saturating nonlinearities. Application to middle ear and basilar membrane vibration, and to audio recording.
Chapter 5 - A preview - If we know what a linear time-invariant system does to sinusoids, we know what it will do to any signal.
Chapter 6 - The frequency response of systems - Amplitude responses as the ratio of output levels to input levels at particular frequencies. Low-pass, high-pass, band-pass and band-stop filters. The use of logarithmic axes (dB vs log Hz). The amplitude response of a cascade of systems. Application to middle ear vibrations and vocal tracts of varying shapes. Formants as resonances. Phase responses, linear and otherwise.
Chapter 7 - The frequency characterization of signals - Fourier analysis and synthesis. The amplitude and phase spectra of periodic signals: sinusoids, sawtooths, square waves, triangle waves and pulse trains. The spectra of aperiodic signals: transients and noise.
Chapter 8 - Signals through systems - Determining the output of systems to specified signals in the frequency domain, for both amplitude and phase. A sawtooth through ideal and realistic low-pass filters. Noise through a filter. Distortion.
Chapter 9 - The time characterization of systems - The notion of an impulse, and the impulse response. The relationship between the frequency response of a system and its impulse response. Determining the frequency response of a set of headphones in 3 ways: via the impulse response, a sinusoid swept in frequency, and white noise.
Chapter 10 - The relationship between the time and frequency domains - Signals short in time tend to be wide in spectrum, and vice versa. 'Windowing' signals to minimise spectral splatter. The trade-off between temporal resolution and frequency resolution in band-pass filters. The relationship between a system's impulse response and its frequency response.
Chapter 11 - Spectrograms: Practical short-term spectral analysis - Determining dynamic spectral changes; the notion of a filter bank; rectification and smoothing; short-term spectra; the use of wide- and narrow-band filters; making spectrograms in the time domain; windowing.
Chapter 12 - Applications to hearing - The measurement of frequency responses, and notions of linearity and nonlinearity in the peripheral auditory system: head and pinna, the ear canal resonance, middle ear vibration, basilar membrane motion; modelling the auditory periphery as a set of systems.
Chapter 13 - Applications to speech production - The source-filter theory of speech production and its application to vowels, diphthongs and fricatives.
Chapter 14 - Digital signals and systems - sampling and quantization; digital-to-analog and analog-to-digital conversion; aliasing; simple digital systems; infinite impulse response (IIR) and finite impulse response (FIR) filters.