Psychoacoustic masking model
Definition
The perceptual model used by lossy codecs such as MP3 and AAC to decide which frequency components can be discarded or coarsely quantised without audible loss. The specific masking thresholds and sub-band structures differ by codec family, leaving identifiable spectral patterns in the encoded file.
Related terms
- Double compression
- The condition in which a video has been encoded at least twice through a lossy codec. The term is also used loosely...
- MEMS microphone
- A Micro-Electro-Mechanical Systems microphone: the capsule type used in virtually all modern smartphones and tablets. MEMS microphones have a characteristically flat midrange...
- Quantisation noise
- The distortion introduced when a continuous audio signal is rounded to discrete digital values. Lossy codecs concentrate quantisation noise at predictable frequency...
- Self-noise (noise floor)
- The electrical noise inherent in a microphone circuit and capsule, measured in dB(A) equivalent input noise. Different microphone types have characteristic noise...
- Spectral fingerprint
- The characteristic frequency response profile of a recording device, including roll-off curves, resonance peaks, and self-noise level. Comparing a recording's spectral fingerprint...
Explained in
- Microphone and Codec Identification in Audio ForensicsThe perceptual model used by lossy codecs such as MP3 and AAC to decide which frequency components can be discarded or coarsely quantised without audible loss....