Line levels refer to the standard signal strength used in audio equipment to transmit sound. These levels are typically measured in volts and are used to connect various devices, such as mixers, amplifiers, and speakers. Line levels ensure that audio signals maintain quality and clarity without distortion. In contrast to microphone levels, which are much lower, line levels provide a stronger signal that can travel longer distances without losing quality. This makes them essential for professional audio setups, where maintaining sound integrity is crucial. Devices that operate at line levels include CD players, digital audio workstations, and synthesizers.