What is the fundamental difference between a lossless and a lossy audio codec?
ALossless formats produce larger files and better sound; lossy formats produce smaller files by permanently removing audio data based on perceptual models
BLossless formats only work on computers; lossy formats work on all devices
CLossless formats use higher sample rates; lossy formats use lower ones
DLossy formats are always inaudibly different from the original; lossless formats are audibly better
Lossless (WAV, FLAC, AIFF) decodes to the exact original audio. Lossy (MP3, AAC, Opus) permanently discards data deemed perceptually irrelevant, achieving smaller files but with potential quality degradation at low bitrates.
Question 2 True / False
True or false: Re-encoding a 320 kbps MP3 to FLAC will produce a lossless, high-quality file equivalent to the original recording.
TTrue
FFalse
Answer: False
FLAC is lossless, but it can only preserve what's in the source file. Converting a lossy MP3 to FLAC captures the already-degraded audio losslessly — the data lost during the original MP3 encoding cannot be recovered.
Question 3 Short Answer
Why does AAC generally sound better than MP3 at the same bitrate?
Think about your answer, then reveal below.
Model answer: AAC uses more sophisticated psychoacoustic models — better frequency resolution, improved temporal masking, and more efficient entropy coding. These improvements allow AAC to retain more perceptually important audio data within the same bitrate budget.
MP3's psychoacoustic model was constrained by 1980s computational limits. AAC was designed a decade later with better models for spectral and temporal masking, more efficient quantization, and tonal/noise component separation.
Question 4 Multiple Choice
A sound effects library sells files for professional post-production use. Which format is most appropriate for the library?
A128 kbps MP3 — small files are easier to download
B320 kbps AAC — high bitrate provides sufficient quality for most uses
C24-bit/96 kHz WAV or BWF — lossless, full fidelity, compatible with all professional DAWs
DOpus at 256 kbps — modern codec, highly efficient
Professional sound effects libraries use lossless, high-resolution WAV or BWF files. Post-production engineers need full fidelity for time-stretching, pitch-shifting, and integration into high-resolution sessions. Lossy compression introduces artifacts that compound under processing.