Transparency (signal processing)
In signal processing, transparency , also known as audibility , describes the properties of a process that ensures that the processed signal cannot be distinguished from the original.
Electroacoustics
In relation to methods of audio data compression , transparency is the name for a quality standard in which the method itself (i.e. regardless of the equipment used) does not affect the quality of the audio signal in a way that is perceptible to the human ear.
While loss-free systems are defined by a metrologically exact, bit-accurate reproduction of the original signal, the transparency of a codec only relates to the acoustic perception by humans. Signal components that cannot be perceived by the human ear according to the psychoacoustic model can be filtered out to save data without this having an audible effect on the sound quality.
Transparency is thus based purely on subjective perception and depends on many factors (experience of the listener, state of hearing, quality of the playback device used, type of piece of music, ambient conditions, etc.), which provides an exact definition of when a codec is referred to as transparent can be difficult. The transparency threshold can therefore only be determined through empirical research using the ABX test . If none of the test subjects is able to reliably distinguish the compressed signal from the original in several passes with a large number of different pieces of music, the codec is considered transparent.
See also
- Transparency (computer system) , the analogous term relating to computer networks
Individual evidence
- ↑ Testing For Audio Transparency , accessed May 29, 2018.