Transparency: Difference between revisions

Revision as of 02:06, 24 August 2006

In psychoacoustics, transparency is the ideal result of lossy data compression. If a lossily compressed result is perceptually indistinguishible from the uncompressed input, then the result can be declared to be transparent. In other words, transparency is the situation where artifacts are nonexistant or imperceptible.

Transparency, like sound quality, is subjective. It depends most on the listener's familiarity with artifacts, and to a lesser extent, the compression method, bitrate used, listening conditions, and listening equipment.

Judging transparency can be difficult due to observation bias, in which subjective like/dislike of a certain compression methodology emotionally influences his/her judgment. This bias is commonly referred to as placebo, although this use is slightly different from the medical use of the term.

There is no way to prove whether a certain compression methodology is transparent. To scientifically prove that a compression method is not transparent, double-blind tests may be useful. The ABX method is normally used.

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 In [[psychoacoustics]], '''transparency''' is the ideal result of [[lossy]] data compression. If a lossily compressed result is '''perceptually''' indistinguishible from the uncompressed input, then the result can be declared to be transparent. In other words, transparency is the situation where [[artifact]]s are nonexistant or imperceptible.
-Transparency, like sound quality, is '''subjective'''. Many listeners are trapped by the ''[[placebo effect]]'', in which subjective like/dislike of a certain compression methodology emotionally influences his/her judgment.
+Transparency, like sound quality, is subjective. It depends most on the listener's familiarity with artifacts, and to a lesser extent, the compression method, [[bitrate]] used, listening conditions, and listening equipment.
-The only way to scientifically prove whether a certain compression methodology is transparent is to perform a '''double-blind''' test using the [[ABX]] method. This also depends on the ability of the listener's ear to properly discern the slight, sometimes very slight, differences between two soundclips.
+Judging transparency can be difficult due to observation bias, in which subjective like/dislike of a certain compression methodology emotionally influences his/her judgment. This bias is commonly referred to as ''placebo,'' although this use is slightly different from the medical use of the term.
+There is no way to prove whether a certain compression methodology is transparent. To scientifically prove that a compression method is ''not'' transparent, double-blind tests may be useful. The [[ABX]] method is normally used.
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