Which encoding format uses lossy data compression and is the de facto standard for digital audio playback?

• A. MPEG
• B. Megapixel
• C. MP3
• D. Multi-point Teleconferencing

Answer: (C)

Lossy compression for digital audio works by discarding information that has little impact on what a listener can perceive, then encoding what remains more efficiently. MP3 uses this perceptual coding idea, applying a psychoacoustic model to remove inaudible or less important parts of the signal and encode the rest at a chosen bitrate. This approach dramatically reduces file size while keeping sound quality that’s acceptable for music playback, which is why MP3 became the widespread standard for digital audio.

MP3 is the specific audio encoding widely adopted, whereas MPEG is a broader family of standards that includes various audio and video codecs, not all of which are used for everyday audio playback. The other options aren’t relevant to digital audio encoding.