What does the sample rate define in audio recording?

The sample rate in audio recording is crucial because it defines how often a sample of the audio signal is taken per second. Measured in Hertz (Hz), the sample rate determines the level of detail captured in the audio recording. For instance, a sample rate of 44.1 kHz means that 44,100 samples are taken every second. This frequency of sampling directly affects the audio quality; a higher sample rate results in better representation of the original sound wave, which leads to clearer and more accurate playback of the audio.

In contrast, the other options relate to different aspects of audio recording. The loudness of audio is controlled by the amplitude, not the sample rate. The number of channels pertains to how audio is mixed and is associated with stereo or mono sound, whereas the duration of the audio file is determined by the length of the recorded content and is not affected by the sample rate itself. Thus, the correct understanding of sample rate as the frequency of sampling is foundational in both recording and audio quality assessment.