What does sample rate indicate in audio files?

• A. The duration of the audio clip.
• B. The number of pieces of data captured each second; higher rates enable recording of higher frequencies.
• C. The bitrate of the file.
• D. The sampling algorithm.

Answer: (B)

Sample rate is how many samples are taken each second when converting sound from analog to digital. Each sample captures the audio amplitude at that moment, so more samples per second give a more precise representation of the waveform. This matters for reproducing higher frequencies: to accurately record frequencies up to a certain limit, you need at least twice that frequency in samples per second (the Nyquist principle). That’s why higher sample rates let you capture higher-frequency content. For example, 44.1 kHz can represent up to about 22 kHz, which is why it's common for CDs, while 48 kHz is standard in video, and 96 or 192 kHz are used for higher-quality audio.

It’s not about how long the clip lasts—duration is separate from sample rate. It’s also not the bitrate, which depends on sample rate along with bit depth and channels, and it’s not the sampling algorithm, which is the method used to convert the analog signal or reconstruct it.