Merge pull request #210356 from sally-baolian/patch-59

Update speech-synthesis-markup.md

Author: prmerger-automator[bot]

articles/cognitive-services/Speech-Service/speech-synthesis-markup.md

@@ -643,15 +643,15 @@ Because prosodic attribute values can vary over a wide range, the speech recogni
 
 | Attribute | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | Required or optional |
 | --------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------- |
-| `pitch`   | Indicates the baseline pitch for the text. You can express the pitch as:<ul><li>An absolute value, expressed as a number followed by "Hz" (Hertz). For example, `<prosody pitch="600Hz">some text</prosody>`.</li><li>A relative value, expressed as a number preceded by "+" or "-" and followed by "Hz" or "st" that specifies an amount to change the pitch. For example: `<prosody pitch="+80Hz">some text</prosody>` or `<prosody pitch="-2st">some text</prosody>`. The "st" indicates the change unit is semitone, which is half of a tone (a half step) on the standard diatonic scale.</li><li>A constant value:<ul><li>x-low</li><li>low</li><li>medium</li><li>high</li><li>x-high</li><li>default</li></ul></li></ul> | Optional             |
+| `pitch`   | Indicates the baseline pitch for the text. You can express the pitch as:<ul><li>An absolute value: Expressed as a number followed by "Hz" (Hertz). For example, `<prosody pitch="600Hz">some text</prosody>`.</li><li>A relative value:<ul><li>As a relative number: Expressed as a number preceded by "+" or "-" and followed by "Hz" or "st" that specifies an amount to change the pitch. For example: `<prosody pitch="+80Hz">some text</prosody>` or `<prosody pitch="-2st">some text</prosody>`. The "st" indicates the change unit is semitone, which is half of a tone (a half step) on the standard diatonic scale.<li>As a percentage: Expressed as a number preceded by "+" (optionally) or "-" and followed by "%", indicating the relative change. For example: `<prosody pitch="50%">some text</prosody>` or `<prosody pitch="-50%">some text</prosody>`.</li></ul></li><li>A constant value:<ul><li>x-low</li><li>low</li><li>medium</li><li>high</li><li>x-high</li><li>default</li></ul></li></ul> | Optional             |
 | `contour` | Contour now supports neural voice. Contour represents changes in pitch. These changes are represented as an array of targets at specified time positions in the speech output. Each target is defined by sets of parameter pairs. For example: <br/><br/>`<prosody contour="(0%,+20Hz) (10%,-2st) (40%,+10Hz)">`<br/><br/>The first value in each set of parameters specifies the location of the pitch change as a percentage of the duration of the text. The second value specifies the amount to raise or lower the pitch by using a relative value or an enumeration value for pitch (see `pitch`).                                                                                                                          | Optional             |
 | `range`   | A value that represents the range of pitch for the text. You can express `range` by using the same absolute values, relative values, or enumeration values used to describe `pitch`.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              | Optional             |
-| `rate`    | Indicates the speaking rate of the text. You can express `rate` as:<ul><li>A relative value, expressed as a number that acts as a multiplier of the default. For example, a value of *1* results in no change in the rate. A value of *0.5* results in a halving of the rate. A value of *3* results in a tripling of the rate.</li><li>A constant value:<ul><li>x-slow</li><li>slow</li><li>medium</li><li>fast</li><li>x-fast</li><li>default</li></ul></li></ul>                                                                                                                                                                                                                                                               | Optional             |
-| `volume`  | Indicates the volume level of the speaking voice. You can express the volume as:<ul><li>An absolute value, expressed as a number in the range of 0.0 to 100.0, from *quietest* to *loudest*. An example is 75. The default is 100.0.</li><li>A relative value, expressed as a number preceded by "+" or "-" that specifies an amount to change the volume. Examples are +10 or -5.5.</li><li>A constant value:<ul><li>silent</li><li>x-soft</li><li>soft</li><li>medium</li><li>loud</li><li>x-loud</li><li>default</li></ul></li></ul>                                                                                                                                                                                           | Optional             |
+| `rate`    | Indicates the speaking rate of the text. You can express `rate` as:<ul><li>A relative value: <ul><li>As a relative number: Expressed as a number that acts as a multiplier of the default. For example, a value of *1* results in no change in the original rate. A value of *0.5* results in a halving of the original rate. A value of *2* results in twice the original rate.</li><li>As a percentage: Expressed as a number preceded by "+" (optionally) or "-" and followed by "%", indicating the relative change. For example: `<prosody rate="50%">some text</prosody>` or `<prosody rate="-50%">some text</prosody>`.</li></ul><li>A constant value:<ul><li>x-slow</li><li>slow</li><li>medium</li><li>fast</li><li>x-fast</li><li>default</li></ul></li></ul>                                                                                                                                                                                                                                                               | Optional             |
+| `volume`  | Indicates the volume level of the speaking voice. You can express the volume as:<ul><li>An absolute value: Expressed as a number in the range of 0.0 to 100.0, from *quietest* to *loudest*. An example is 75. The default is 100.0.</li><li>A relative value: <ul><li>As a relative number: Expressed as a number preceded by "+" or "-" that specifies an amount to change the volume. Examples are +10 or -5.5.</li><li>As a percentage: Expressed as a number preceded by "+" (optionally) or "-" and followed by "%", indicating the relative change. For example: `<prosody volume="50%">some text</prosody>` or `<prosody volume="+3%">some text</prosody>`.</li></ul><li>A constant value:<ul><li>silent</li><li>x-soft</li><li>soft</li><li>medium</li><li>loud</li><li>x-loud</li><li>default</li></ul></li></ul>                                                                                                                                                                                           | Optional             |
 
 ### Change speaking rate
 
-Speaking rate can be applied at the word or sentence level.
+Speaking rate can be applied at the word or sentence level. The rate changes should be within 0.5 to 2 times the original audio.
 
 **Example**
 
@@ -667,7 +667,7 @@ Speaking rate can be applied at the word or sentence level.
 
 ### Change volume
 
-Volume changes can be applied at the sentence level.
+Volume changes can be applied at the sentence level. The volume changes should be within 0 (silence) to 1.5 times the original audio.
 
 **Example**
 
@@ -683,7 +683,7 @@ Volume changes can be applied at the sentence level.
 
 ### Change pitch
 
-Pitch changes can be applied at the sentence level.
+Pitch changes can be applied at the sentence level. The pitch changes should be within 0.5 to 1.5 times the original audio.
 
 **Example**