Lecture notes on neural systems, hearing, anatomy of the ear, the auditory nerve, pure tones, auditory nerve responses, sound waves, the properties of the basilar membrane, place code for frequency, Fourier analysis, measures of frequency content, periodic signals, the TRPA1 channel, hair cells, tonotopic maps, the primary auditory cortex, interaural time delay, superior olive neurons, axonal delay lines, and vertical localization.