Which factors can contribute to audio distortion?

Audio distortion occurs when the signal level exceeds the capacity of the equipment, leading to a compressed and altered sound. When input levels are overloaded, it can result in clipping, which produces a harsh, distorted sound that can significantly degrade audio quality. This distortion typically occurs because the electronic components in the audio chain cannot properly handle the excessive signal strength, causing them to "clip" the peaks of the sound waves.

While high-quality cables can help reduce interference and signal loss, improper microphone placement may affect sound quality without causing distortion directly. Similarly, maintaining low output levels generally helps avoid distortion rather than leading to it. Thus, the factor that directly causes audio distortion is overloading the input levels, making this choice the correct one.