What type of communication do audio systems primarily support?

Audio systems are designed specifically to capture, process, and reproduce sound. Their primary function is to facilitate sound communication, making them integral to various applications such as music playback, public address systems, and telecommunication. This focuses on auditory experience, conveying information through sound waves, which is why sound communication is the correct answer.

While visual communication and data transmission might occur alongside audio systems (for example, in audiovisual systems), they do not represent the primary function of audio systems. Signal routing is also important within audio setups for managing how sound signals are directed and processed, but again, it serves a supporting role to the primary purpose of communicating sound. Thus, the emphasis remains on sound communication as the central focus of audio systems.