Dither - Revision history

Brad Johnson at 22:03, 9 August 2017

2017-08-09T22:03:05Z

Brad Johnson at 23:01, 18 July 2017

2017-07-18T23:01:30Z

Brad Johnson at 22:56, 18 July 2017

2017-07-18T22:56:03Z

Brad Johnson at 19:14, 6 February 2014

2014-02-06T19:14:34Z

Brad Johnson at 23:18, 3 July 2012

2012-07-03T23:18:55Z

Brad Johnson at 23:17, 3 July 2012

2012-07-03T23:17:26Z

Brad Johnson at 23:16, 3 July 2012

2012-07-03T23:16:58Z

Brad Johnson at 23:15, 3 July 2012

2012-07-03T23:15:21Z

Brad Johnson at 23:15, 3 July 2012

2012-07-03T23:15:01Z

Brad Johnson at 23:13, 3 July 2012

2012-07-03T23:13:09Z

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 =Overview=
-The term <nowiki>dither</nowiki> is used to describe a special form of wide-band noise that is added to a digital audio signal after the [[wordlength]] is reduced. The purpose is to randomize quantization error of low level signals.
+The term <nowiki>dither</nowiki> is used to describe a special form of wide-band noise that is added to a digital audio signal after the [[wordlength]] is reduced. The purpose is to randomize [[quantization]] error of low level signals.
 =Basics=
 In digital audio, the original analog signal [[amplitude]] must be encoded in discrete "steps." The number of possible steps is determined by the [[wordlength]]. For high level (large amplitude) signals, the "step size" relative to the signal is small and the resulting quantization error caused by "rounding up or rounding down" to the closest discrete step is small.

@@ Line 6: / Line 6: @@
 At very low signal levels (small amplitude); the error becomes quite significant and the effect is a clearly audible distortion that increases in level as signal level decreases to the least significant bit ([[lsb]]) level. By randomizing the error; the distortion is eliminated and this results in a perceived increase in the [[dynamic range]] even though the addition of dither (noise) actually decreases the ''measurable'' dynamic range.
-There are a number of different types of dither; with "Flat" and "Triangular" or "HPDF" (high pass probability density function) used commonly in digital audio. Both distribute the noise energy fairly evenly across the audible spectrum. An additional process known as Noise shaping can be applied to effectively "shift" the noise energy away from the midrange where the human ear is most sensitive to the bass and upper treble regions.
+There are a number of different types of dither; with "Flat" and "Triangular" or "HPDF" (High-pass Probability Density Function) used commonly in digital audio. Both distribute the noise energy fairly evenly across the audible spectrum. Flat dither is preferable for encoding audio which will undergo further processing and Triangular dither is generally preferred for final encoding and wordlength reduction.
 For additional information; also see:

@@ Line 1: / Line 1: @@
 =Overview=
-The term <nowiki>dither</nowiki> is used to describe a special form of wide-band noise that is added to a digital audio signal before the [[wordlength]] is reduced. The purpose is to randomize quantization error of low level signals.
+The term <nowiki>dither</nowiki> is used to describe a special form of wide-band noise that is added to a digital audio signal after the [[wordlength]] is reduced. The purpose is to randomize quantization error of low level signals.
 =Basics=
 In digital audio, the original analog signal [[amplitude]] must be encoded in discrete "steps." The number of possible steps is determined by the [[wordlength]]. For high level (large amplitude) signals, the "step size" relative to the signal is small and the resulting quantization error caused by "rounding up or rounding down" to the closest discrete step is small.
-At very low signal levels (small amplitude); the error becomes quite significant and the audible effect is a very audible distortion that increases in level as signal level decreases to the least significant bit ([[lsb]]) level. By randomizing the error; the distortion is eliminated and this results in a perceived increase in the [[dynamic range]] even though the addition of dither (noise) actually decreases the ''measurable'' dynamic range.
+At very low signal levels (small amplitude); the error becomes quite significant and the effect is a clearly audible distortion that increases in level as signal level decreases to the least significant bit ([[lsb]]) level. By randomizing the error; the distortion is eliminated and this results in a perceived increase in the [[dynamic range]] even though the addition of dither (noise) actually decreases the ''measurable'' dynamic range.
 There are a number of different types of dither; with "Flat" and "Triangular" or "HPDF" (high pass probability density function) used commonly in digital audio. Both distribute the noise energy fairly evenly across the audible spectrum. An additional process known as Noise shaping can be applied to effectively "shift" the noise energy away from the midrange where the human ear is most sensitive to the bass and upper treble regions.

@@ Line 1: / Line 1: @@
 =Overview=
-The term <nowiki>dither</nowiki> is used to describe a special form of wide-band noise that is added to a digital audio signal after the [[wordlength]] is reduced. The purpose is to randomize quantization error of low level signals.
+The term <nowiki>dither</nowiki> is used to describe a special form of wide-band noise that is added to a digital audio signal before the [[wordlength]] is reduced. The purpose is to randomize quantization error of low level signals.
 =Basics=
 In digital audio, the original analog signal [[amplitude]] must be encoded in discrete "steps." The number of possible steps is determined by the [[wordlength]]. For high level (large amplitude) signals, the "step size" relative to the signal is small and the resulting quantization error caused by "rounding up or rounding down" to the closest discrete step is small.

@@ Line 6: / Line 6: @@
 At very low signal levels (small amplitude); the error becomes quite significant and the audible effect is a very audible distortion that increases in level as signal level decreases to the least significant bit ([[lsb]]) level. By randomizing the error; the distortion is eliminated and this results in a perceived increase in the [[dynamic range]] even though the addition of dither (noise) actually decreases the ''measurable'' dynamic range.
-There are a number of different types of dither; with "Flat" and "Triangular" or "HPDF" (high pass probability density function)being common in digital audio. Both distribute the noise energy fairly evenly across the audible spectrum. An additional process known as Noise shaping can be applied to effectively "shift" the noise energy away from the midrange where the human ear is most sensitive to the bass and upper treble regions.
+There are a number of different types of dither; with "Flat" and "Triangular" or "HPDF" (high pass probability density function) used commonly in digital audio. Both distribute the noise energy fairly evenly across the audible spectrum. An additional process known as Noise shaping can be applied to effectively "shift" the noise energy away from the midrange where the human ear is most sensitive to the bass and upper treble regions.
 For additional information; also see:

@@ Line 11: / Line 11: @@
 * [[Acoustic bit correction]]
-[http://en.wikipedia.org/wiki/Dither For more detailed information on Dither click here]
+*[http://en.wikipedia.org/wiki/Dither For more detailed information on Dither click here]
-[http://en.wikipedia.org/wiki/Noise_shaping For more detailed information on Noise shaping click here]
+*[http://en.wikipedia.org/wiki/Noise_shaping For more detailed information on Noise shaping click here]
 [[Category:Audio conversion]]
 [[Category:Terminology]]