This contribution provides an overview of optical techniques for sound recording, sound synthesis, and sound processing. Several applications of optical devices, examples, and references describing the history and current trends in this field will be given. For sound recording, optical devices can be used to capture vibrations and to transform mechanical sound waves into an electrical signal. Optical storage of audio has a long history beginning with analog sound tracks on film up to recent optical media as for example the Blue-ray Disc. For sound synthesis based on optical systems we will give examples based on graphical sound and the photo-sonic disc for time-domain synthesis. Frequency-domain synthesis techniques which are controlled by a time-frequency (image domain) signal representation will be explained. For analog sound processing the use of a light emitting diode coupled to a photo-electric cell (light dependent resistor) constitutes a nonlinear two-port electrical network or element. These optocouplers have still a wide range of applications for switching, gating, and volume control of audio signals due to their special nonlinear behavior. Hence, there exists a broad interest for high-quality discrete-time models of these devices. An overview of several applications with these optical nonlinearities will be given.