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 topeak, rms; dB scales.
Chapter 4  Introduction to systems  Linearity, additivity, homogeneity and timeinvariance. Saturating nonlinearities. Application to middle ear and basilar membrane vibration, and to audio recording.
Chapter 5  A preview  If we know what a linear timeinvariant 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. Lowpass, highpass, bandpass and bandstop 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 lowpass 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 tradeoff between temporal resolution and frequency resolution in bandpass filters. The relationship between a system's impulse response and its frequency response.
Chapter 11  Spectrograms: Practical shortterm spectral analysis  Determining dynamic spectral changes; the notion of a filter bank; rectification and smoothing; shortterm spectra; the use of wide and narrowband 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 sourcefilter theory of speech production and its application to vowels, diphthongs and fricatives.
Chapter 14  Digital signals and systems  sampling and quantization; digitaltoanalog and analogtodigital conversion; aliasing; simple digital systems; infinite impulse response (IIR) and finite impulse response (FIR) filters.
