What does an amplifier do in a sound system?

An amplifier plays a crucial role in a sound system by increasing the signal strength of a sound source. This process is essential for ensuring that audio signals can be sent effectively to speakers, allowing them to produce sound at levels that are appropriate for the listening environment. When audio signals are weak, they may not be capable of driving speakers to produce audible sound, leading to poor audio performance. By amplifying these signals, the amplifier ensures that the resulting output is loud enough and maintains the quality of the original sound.

In contrast, other functions mentioned in the incorrect options do not accurately represent the role of an amplifier. For instance, turning sound into visual signals is related more to devices like projectors or screens, while decreasing the volume refers to a function of a volume control mechanism rather than an amplifier. Similarly, acting as a speaker would be a function of transducers in a sound system, not the amplifier itself. Thus, the accurate definition of an amplifier’s role aligns with the function of increasing the strength of sound signals.