How is sound defined in the context of audio equipment?

In the context of audio equipment, sound is accurately defined as vibrations that can be perceived. Sound is produced when an object vibrates, creating pressure waves in the air (or another medium) that travel and can be detected by the human ear. This understanding is fundamental to audio equipment design and function, as various components such as microphones, speakers, and amplifiers are engineered to capture, process, and reproduce these sound vibrations effectively.

The other options describe aspects related to audio technology but do not define sound itself. For instance, electrical signals transmitted through wires relate more to the transmission of sound rather than its fundamental nature. Light waves interpreted by human ears is an incorrect notion, as sound does not involve light but rather mechanical vibrations. Similarly, signals recorded by digital devices pertain to the ways sound can be captured and stored, rather than the intrinsic definition of sound itself as a phenomenon. Hence, describing sound as vibrations that can be perceived is the most accurate and relevant definition in the context of audio equipment.