Pronunciation Lexicon Specification: Difference between revisions
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{{Short description|World Wide Web Consortium recommendation}} |
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⚫ | The '''Pronunciation Lexicon Specification''' ( |
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{{Use American English|date = January 2019}} |
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⚫ | The '''Pronunciation Lexicon Specification''' (PLS) is a [[W3C]] Recommendation, which is designed to enable interoperable specification of pronunciation information for both [[speech recognition]] and [[speech synthesis]] engines within voice browsing applications. The language is intended to be easy to use by developers while supporting the accurate specification of pronunciation information for international use. |
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⚫ | The language allows one or more pronunciations for a word or phrase to be specified using a standard pronunciation alphabet or if necessary using vendor specific alphabets. Pronunciations are grouped together into a PLS document which may be referenced from other markup languages, such as the Speech Recognition Grammar Specification [[SRGS]] and the Speech Synthesis Markup Language [[SSML]]. |
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⚫ | The language allows one or more pronunciations for a word or phrase to be specified using a standard pronunciation alphabet or if necessary using vendor specific alphabets. Pronunciations are grouped together into a PLS document which may be referenced from other markup languages, such as the Speech Recognition Grammar Specification [[SRGS]] and the Speech Synthesis Markup Language [[Speech Synthesis Markup Language|SSML]]. |
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==Usage== |
==Usage== |
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Here is an example PLS document: |
Here is an example PLS document: |
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<syntaxhighlight lang="xml"> |
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<?xml version="1.0" encoding="UTF-8"?> |
<?xml version="1.0" encoding="UTF-8"?> |
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<lexicon version="1.0" |
<lexicon version="1.0" |
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<grapheme>judgment</grapheme> |
<grapheme>judgment</grapheme> |
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<grapheme>judgement</grapheme> |
<grapheme>judgement</grapheme> |
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<phoneme> |
<phoneme>ˈdʒʌdʒ.mənt</phoneme> |
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<!-- IPA string is: |
<!-- IPA string is: |
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" |
"ˈdʒʌdʒ.mənt" --> |
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</lexeme> |
</lexeme> |
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<lexeme> |
<lexeme> |
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<grapheme>fiancé</grapheme> |
<grapheme>fiancé</grapheme> |
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<grapheme>fiance</grapheme> |
<grapheme>fiance</grapheme> |
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<phoneme> |
<phoneme>fiˈɒns.eɪ</phoneme> |
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<!-- IPA string is: |
<!-- IPA string is: |
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" |
"fiˈɒns.eɪ" --> |
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<phoneme> |
<phoneme>ˌfiː.ɑːnˈseɪ</phoneme> |
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<!-- IPA string is: |
<!-- IPA string is: |
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"ˌfiː.ɑːnˈseɪ" --> |
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"ˌfiː.ɑːnˈseɪ" --> |
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</lexeme> |
</lexeme> |
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</lexicon> |
</lexicon> |
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</syntaxhighlight> |
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which could be used to improve [[speech synthesis|TTS]] as shown in the following [[ |
which could be used to improve [[speech synthesis|TTS]] as shown in the following [[Speech Synthesis Markup Language|SSML 1.0]] document: |
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<syntaxhighlight lang="xml"> |
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<?xml version="1.0" encoding="UTF-8"?> |
<?xml version="1.0" encoding="UTF-8"?> |
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<speak version="1.0" |
<speak version="1.0" |
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xml:lang="en-US"> |
xml:lang="en-US"> |
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<lexicon uri="http://www.example.org/lexicon_defined_above.xml"/> |
<lexicon uri="http://www.example.org/lexicon_defined_above.xml"/> |
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<p> In the judgement of my fiancé, Las Vegas is the best place for a honeymoon. |
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I replied that I preferred Venice and didn't think the Venetian casino was an |
I replied that I preferred Venice and didn't think the Venetian casino was an |
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acceptable compromise. |
acceptable compromise.</p> |
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</speak> |
</speak> |
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</syntaxhighlight> |
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but also to improve [[ASR]] in the following [[SRGS|SRGS 1.0]] grammar: |
but also to improve [[Speech_recognition|ASR]] in the following [[SRGS|SRGS 1.0]] grammar: |
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<syntaxhighlight lang="xml"> |
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<?xml version="1.0" encoding="UTF-8"?> |
<?xml version="1.0" encoding="UTF-8"?> |
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<grammar version="1.0" |
<grammar version="1.0" |
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</rule> |
</rule> |
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</grammar> |
</grammar> |
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</syntaxhighlight> |
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==Common |
==Common use cases== |
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===Multiple pronunciations for the same orthography=== |
===Multiple pronunciations for the same orthography=== |
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For [[ASR]] systems it is common to rely on multiple pronunciations of the same word or phrase in order to cope with variations of pronunciation within a language. In the |
For [[Speech recognition|ASR]] systems it is common to rely on multiple pronunciations of the same word or phrase in order to cope with variations of pronunciation within a language. In the Pronunciation Lexicon language, multiple pronunciations are represented by more than one <phoneme> (or <alias>) element within the same <lexeme> element. |
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In the following example the word "Newton" has two possible pronunciations. |
In the following example the word "Newton" has two possible pronunciations. |
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<syntaxhighlight lang="xml"> |
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<?xml version="1.0" encoding="UTF-8"?> |
<?xml version="1.0" encoding="UTF-8"?> |
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<lexicon version="1.0" |
<lexicon version="1.0" |
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<lexeme> |
<lexeme> |
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<grapheme>Newton</grapheme> |
<grapheme>Newton</grapheme> |
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<phoneme> |
<phoneme>ˈnjuːtən</phoneme> |
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<!-- IPA string is: " |
<!-- IPA string is: "ˈnjuːtən" --> |
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<phoneme> |
<phoneme>ˈnuːtən</phoneme> |
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<!-- IPA string is: " |
<!-- IPA string is: "ˈnuːtən" --> |
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</lexeme> |
</lexeme> |
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</lexicon> |
</lexicon> |
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</syntaxhighlight> |
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===Multiple orthographies=== |
===Multiple orthographies=== |
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In some situations there are alternative textual representations for the same word or phrase. This can arise due to a number of reasons. See Section 4.5 of |
In some situations there are alternative textual representations for the same word or phrase. This can arise due to a number of reasons. See Section 4.5 of PLS for details. Because these are representations that have the same meaning (as opposed to homophones), it is recommended that they be represented using a single <lexeme> element that contains multiple graphemes. |
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Here are two simple examples of multiple orthographies: alternative spelling of an English word and multiple writings of a Japanese word. |
Here are two simple examples of multiple orthographies: alternative spelling of an English word and multiple writings of a Japanese word. |
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<syntaxhighlight lang="xml"> |
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<?xml version="1.0" encoding="UTF-8"?> |
<?xml version="1.0" encoding="UTF-8"?> |
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<lexicon version="1.0" |
<lexicon version="1.0" |
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<grapheme>colour</grapheme> |
<grapheme>colour</grapheme> |
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<grapheme>color</grapheme> |
<grapheme>color</grapheme> |
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<phoneme> |
<phoneme>ˈkʌlər</phoneme> |
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<!-- IPA string is: " |
<!-- IPA string is: "ˈkʌlər" --> |
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</lexeme> |
</lexeme> |
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</lexicon> |
</lexicon> |
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<?xml version="1.0" encoding="UTF-8"?> |
<?xml version="1.0" encoding="UTF-8"?> |
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xsi:schemaLocation="http://www.w3.org/2005/01/pronunciation-lexicon |
xsi:schemaLocation="http://www.w3.org/2005/01/pronunciation-lexicon |
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http://www.w3.org/TR/2007/CR-pronunciation-lexicon-20071212/pls.xsd" |
http://www.w3.org/TR/2007/CR-pronunciation-lexicon-20071212/pls.xsd" |
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alphabet="ipa" xml:lang=" |
alphabet="ipa" xml:lang="ja"> |
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<!-- Japanese entry showing how multiple writing systems are handled |
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romaji, kanji and hiragana orthographies --> |
romaji, kanji and hiragana orthographies --> |
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<lexeme> |
<lexeme> |
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<grapheme>日本語</grapheme> |
<grapheme>日本語</grapheme> |
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<grapheme>にほんご</grapheme> |
<grapheme>にほんご</grapheme> |
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<phoneme> |
<phoneme>ɲihoŋɡo</phoneme> |
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<!-- IPA string is: " |
<!-- IPA string is: "ɲihoŋɡo" --> |
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</lexeme> |
</lexeme> |
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</lexicon> |
</lexicon> |
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</syntaxhighlight> |
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===Homophones=== |
===Homophones=== |
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Most languages have [[homophones]], words with the same pronunciation but different meanings (and possibly different spellings), for instance "seed" and "cede". It is recommended that these be represented as different lexemes. |
Most languages have [[homophones]], words with the same pronunciation but different meanings (and possibly different spellings), for instance "seed" and "cede". It is recommended that these be represented as different lexemes. |
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<syntaxhighlight lang="xml"> |
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<?xml version="1.0" encoding="UTF-8"?> |
<?xml version="1.0" encoding="UTF-8"?> |
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<lexicon version="1.0" |
<lexicon version="1.0" |
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<lexeme> |
<lexeme> |
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<grapheme>cede</grapheme> |
<grapheme>cede</grapheme> |
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<phoneme> |
<phoneme>siːd</phoneme> |
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<!-- IPA string is: " |
<!-- IPA string is: "siːd" --> |
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</lexeme> |
</lexeme> |
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<lexeme> |
<lexeme> |
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<grapheme>seed</grapheme> |
<grapheme>seed</grapheme> |
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<phoneme> |
<phoneme>siːd</phoneme> |
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<!-- IPA string is: " |
<!-- IPA string is: "siːd" --> |
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</lexeme> |
</lexeme> |
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</lexicon> |
</lexicon> |
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</syntaxhighlight> |
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===Homographs=== |
===Homographs=== |
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Most languages have words with different meanings but the same spelling (and sometimes different pronunciations), called [[homographs]]. For example, in English the word bass (fish) and the word bass (in music) have identical spellings but different meanings and pronunciations. Although it is recommended that these words be represented using separate |
Most languages have words with different meanings but the same spelling (and sometimes different pronunciations), called [[homographs]]. For example, in English the word bass (fish) and the word bass (in music) have identical spellings but different meanings and pronunciations. Although it is recommended that these words be represented using separate <lexeme> elements that are distinguished by different values of the role attribute (see Section 4.4 of PLS 1.0), if a pronunciation lexicon author does not want to distinguish between the two words they could simply be represented as alternative pronunciations within the same <lexeme> element. In the latter case the [[speech synthesis|TTS]] processor will not be able to distinguish when to apply the first or the second transcription. |
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In this example the pronunciations of the homograph "bass" are shown. |
In this example the pronunciations of the homograph "bass" are shown. |
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<syntaxhighlight lang="xml"> |
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<?xml version="1.0" encoding="UTF-8"?> |
<?xml version="1.0" encoding="UTF-8"?> |
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<lexicon version="1.0" |
<lexicon version="1.0" |
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<lexeme> |
<lexeme> |
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<grapheme>bass</grapheme> |
<grapheme>bass</grapheme> |
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<phoneme> |
<phoneme>bæs</phoneme> |
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<!-- IPA string is: |
<!-- IPA string is: bæs --> |
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<phoneme> |
<phoneme>beɪs</phoneme> |
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<!-- IPA string is: |
<!-- IPA string is: beɪs --> |
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</lexeme> |
</lexeme> |
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</lexicon> |
</lexicon> |
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</syntaxhighlight> |
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Note that English contains numerous examples of noun-verb pairs that can be treated either as [[homographs]] or as alternative pronunciations, depending on author preference. Two examples are the noun/verb "refuse" and the noun/verb "address". |
Note that English contains numerous examples of noun-verb pairs that can be treated either as [[homographs]] or as alternative pronunciations, depending on author preference. Two examples are the noun/verb "refuse" and the noun/verb "address". |
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<syntaxhighlight lang="xml"> |
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<?xml version="1.0" encoding="UTF-8"?> |
<?xml version="1.0" encoding="UTF-8"?> |
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<lexicon version="1.0" |
<lexicon version="1.0" |
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<lexeme role="mypos:verb"> |
<lexeme role="mypos:verb"> |
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<grapheme>refuse</grapheme> |
<grapheme>refuse</grapheme> |
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<phoneme> |
<phoneme>rɪˈfjuːz</phoneme> |
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<!-- IPA string is: " |
<!-- IPA string is: "rɪˈfjuːz" --> |
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</lexeme> |
</lexeme> |
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<lexeme role="mypos:noun"> |
<lexeme role="mypos:noun"> |
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<grapheme>refuse</grapheme> |
<grapheme>refuse</grapheme> |
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<phoneme> |
<phoneme>ˈrɛfjuːs</phoneme> |
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<!-- IPA string is: " |
<!-- IPA string is: "ˈrɛfjuːs" --> |
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</lexeme> |
</lexeme> |
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</lexicon> |
</lexicon> |
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</syntaxhighlight> |
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===Pronunciation by |
===Pronunciation by orthography=== |
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⚫ | For some words and phrases pronunciation can be expressed quickly and conveniently as a sequence of other [[orthographies]]. The developer is not required to have linguistic knowledge, but instead makes use of the [[pronunciations]] that are already expected to be available. To express pronunciations using other orthographies the <alias> element may be used. |
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⚫ | For some words and phrases pronunciation can be expressed quickly and conveniently as a sequence of other [[orthographies]]. The developer is not required to have linguistic knowledge, but instead makes use of the [[pronunciations]] that are already expected to be available. To express pronunciations using other orthographies the |
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This feature may be very useful to deal with acronym expansion. |
This feature may be very useful to deal with acronym expansion. |
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<syntaxhighlight lang="xml"> |
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<?xml version="1.0" encoding="UTF-8"?> |
<?xml version="1.0" encoding="UTF-8"?> |
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<lexicon version="1.0" |
<lexicon version="1.0" |
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http://www.w3.org/TR/2007/CR-pronunciation-lexicon-20071212/pls.xsd" |
http://www.w3.org/TR/2007/CR-pronunciation-lexicon-20071212/pls.xsd" |
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alphabet="ipa" xml:lang="en-US"> |
alphabet="ipa" xml:lang="en-US"> |
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<!-- |
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Acronym expansion |
Acronym expansion |
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--> |
--> |
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<alias>World Wide Web Consortium</alias> |
<alias>World Wide Web Consortium</alias> |
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</lexeme> |
</lexeme> |
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<!-- |
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number representation |
number representation |
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--> |
--> |
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<alias>one hundred and one</alias> |
<alias>one hundred and one</alias> |
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</lexeme> |
</lexeme> |
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<!-- |
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crude pronunciation mechanism |
crude pronunciation mechanism |
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--> |
--> |
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<alias>tie land</alias> |
<alias>tie land</alias> |
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</lexeme> |
</lexeme> |
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<!-- |
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crude pronunciation mechanism and acronym expansion |
crude pronunciation mechanism and acronym expansion |
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--> |
--> |
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</lexeme> |
</lexeme> |
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</lexicon> |
</lexicon> |
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</syntaxhighlight> |
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==Status and |
==Status and future== |
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*PLS 1.0 reached the status of W3C Recommendation on 14 October 2008. |
*PLS 1.0 reached the status of W3C Recommendation on 14 October 2008. |
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⚫ | |||
⚫ | |||
==See also== |
==See also== |
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* [[VoiceXML]] |
* [[VoiceXML]] |
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* [[SRGS]] |
* [[SRGS]] |
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* [[SSML]] |
* [[Speech Synthesis Markup Language|SSML]] |
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* [[SISR]] |
* [[SISR]] |
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⚫ | |||
⚫ | |||
==External links== |
==External links== |
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* [http://www.w3.org/TR/speech-synthesis/ SSML Specification (W3C Recommendation)] |
* [http://www.w3.org/TR/speech-synthesis/ SSML Specification (W3C Recommendation)] |
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* [http://www.voicexml.org VoiceXML Forum] |
* [http://www.voicexml.org VoiceXML Forum] |
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* [http://www.orange.com/en_EN/innovation/ |
* [http://www.orange.com/en_EN/innovation/software_licensing/Software/PLS.jsp France Telecom Orange Labs implementation of PLS 1.0 under the Gnu General Public License version 3] |
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* [http://sourceforge.net/projects/openpls |
* [http://sourceforge.net/projects/openpls SourceForge project for Java-based implementation of PLS 1.0] |
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{{compu-lang-stub}} |
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{{W3C standards}} |
{{W3C standards}} |
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[[Category:World Wide Web Consortium standards]] |
[[Category:World Wide Web Consortium standards]] |
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[[Category:XML-based standards]] |
[[Category:XML-based standards]] |
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[[Category:Speech synthesis software]] |
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[[Category:Speech recognition software]] |
Latest revision as of 13:19, 15 December 2023
The Pronunciation Lexicon Specification (PLS) is a W3C Recommendation, which is designed to enable interoperable specification of pronunciation information for both speech recognition and speech synthesis engines within voice browsing applications. The language is intended to be easy to use by developers while supporting the accurate specification of pronunciation information for international use.
The language allows one or more pronunciations for a word or phrase to be specified using a standard pronunciation alphabet or if necessary using vendor specific alphabets. Pronunciations are grouped together into a PLS document which may be referenced from other markup languages, such as the Speech Recognition Grammar Specification SRGS and the Speech Synthesis Markup Language SSML.
Usage
[edit]Here is an example PLS document:
<?xml version="1.0" encoding="UTF-8"?>
<lexicon version="1.0"
xmlns="http://www.w3.org/2005/01/pronunciation-lexicon"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3.org/2005/01/pronunciation-lexicon
http://www.w3.org/TR/2007/CR-pronunciation-lexicon-20071212/pls.xsd"
alphabet="ipa" xml:lang="en-US">
<lexeme>
<grapheme>judgment</grapheme>
<grapheme>judgement</grapheme>
<phoneme>ˈdʒʌdʒ.mənt</phoneme>
<!-- IPA string is:
"ˈdʒʌdʒ.mənt" -->
</lexeme>
<lexeme>
<grapheme>fiancé</grapheme>
<grapheme>fiance</grapheme>
<phoneme>fiˈɒns.eɪ</phoneme>
<!-- IPA string is:
"fiˈɒns.eɪ" -->
<phoneme>ˌfiː.ɑːnˈseɪ</phoneme>
<!-- IPA string is:
"ˌfiː.ɑːnˈseɪ" -->
</lexeme>
</lexicon>
which could be used to improve TTS as shown in the following SSML 1.0 document:
<?xml version="1.0" encoding="UTF-8"?>
<speak version="1.0"
xmlns="http://www.w3.org/2001/10/synthesis"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3.org/2001/10/synthesis
http://www.w3.org/TR/speech-synthesis/synthesis.xsd"
xml:lang="en-US">
<lexicon uri="http://www.example.org/lexicon_defined_above.xml"/>
<p> In the judgement of my fiancé, Las Vegas is the best place for a honeymoon.
I replied that I preferred Venice and didn't think the Venetian casino was an
acceptable compromise.</p>
</speak>
but also to improve ASR in the following SRGS 1.0 grammar:
<?xml version="1.0" encoding="UTF-8"?>
<grammar version="1.0"
xmlns="http://www.w3.org/2001/06/grammar"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3.org/2001/06/grammar
http://www.w3.org/TR/speech-grammar/grammar.xsd"
xml:lang="en-US" root="movies" mode="voice">
<lexicon uri="http://www.example.org/lexicon_defined_above.xml"/>
<rule id="movies" scope="public">
<one-of>
<item>Terminator 2: Judgment Day</item>
<item>My Big Fat Obnoxious Fiance</item>
<item>Pluto's Judgement Day</item>
</one-of>
</rule>
</grammar>
Common use cases
[edit]Multiple pronunciations for the same orthography
[edit]For ASR systems it is common to rely on multiple pronunciations of the same word or phrase in order to cope with variations of pronunciation within a language. In the Pronunciation Lexicon language, multiple pronunciations are represented by more than one <phoneme> (or <alias>) element within the same <lexeme> element.
In the following example the word "Newton" has two possible pronunciations.
<?xml version="1.0" encoding="UTF-8"?>
<lexicon version="1.0"
xmlns="http://www.w3.org/2005/01/pronunciation-lexicon"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3.org/2005/01/pronunciation-lexicon
http://www.w3.org/TR/2007/CR-pronunciation-lexicon-20071212/pls.xsd"
alphabet="ipa" xml:lang="en-GB">
<lexeme>
<grapheme>Newton</grapheme>
<phoneme>ˈnjuːtən</phoneme>
<!-- IPA string is: "ˈnjuːtən" -->
<phoneme>ˈnuːtən</phoneme>
<!-- IPA string is: "ˈnuːtən" -->
</lexeme>
</lexicon>
Multiple orthographies
[edit]In some situations there are alternative textual representations for the same word or phrase. This can arise due to a number of reasons. See Section 4.5 of PLS for details. Because these are representations that have the same meaning (as opposed to homophones), it is recommended that they be represented using a single <lexeme> element that contains multiple graphemes.
Here are two simple examples of multiple orthographies: alternative spelling of an English word and multiple writings of a Japanese word.
<?xml version="1.0" encoding="UTF-8"?>
<lexicon version="1.0"
xmlns="http://www.w3.org/2005/01/pronunciation-lexicon"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3.org/2005/01/pronunciation-lexicon
http://www.w3.org/TR/2007/CR-pronunciation-lexicon-20071212/pls.xsd"
alphabet="ipa" xml:lang="en-US">
<!-- English entry showing how alternative spellings are handled -->
<lexeme>
<grapheme>colour</grapheme>
<grapheme>color</grapheme>
<phoneme>ˈkʌlər</phoneme>
<!-- IPA string is: "ˈkʌlər" -->
</lexeme>
</lexicon>
<?xml version="1.0" encoding="UTF-8"?>
<lexicon version="1.0"
xmlns="http://www.w3.org/2005/01/pronunciation-lexicon"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3.org/2005/01/pronunciation-lexicon
http://www.w3.org/TR/2007/CR-pronunciation-lexicon-20071212/pls.xsd"
alphabet="ipa" xml:lang="ja">
<!-- Japanese entry showing how multiple writing systems are handled
romaji, kanji and hiragana orthographies -->
<lexeme>
<grapheme>nihongo</grapheme>
<grapheme>日本語</grapheme>
<grapheme>にほんご</grapheme>
<phoneme>ɲihoŋɡo</phoneme>
<!-- IPA string is: "ɲihoŋɡo" -->
</lexeme>
</lexicon>
Homophones
[edit]Most languages have homophones, words with the same pronunciation but different meanings (and possibly different spellings), for instance "seed" and "cede". It is recommended that these be represented as different lexemes.
<?xml version="1.0" encoding="UTF-8"?>
<lexicon version="1.0"
xmlns="http://www.w3.org/2005/01/pronunciation-lexicon"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3.org/2005/01/pronunciation-lexicon
http://www.w3.org/TR/2007/CR-pronunciation-lexicon-20071212/pls.xsd"
alphabet="ipa" xml:lang="en-US">
<lexeme>
<grapheme>cede</grapheme>
<phoneme>siːd</phoneme>
<!-- IPA string is: "siːd" -->
</lexeme>
<lexeme>
<grapheme>seed</grapheme>
<phoneme>siːd</phoneme>
<!-- IPA string is: "siːd" -->
</lexeme>
</lexicon>
Homographs
[edit]Most languages have words with different meanings but the same spelling (and sometimes different pronunciations), called homographs. For example, in English the word bass (fish) and the word bass (in music) have identical spellings but different meanings and pronunciations. Although it is recommended that these words be represented using separate <lexeme> elements that are distinguished by different values of the role attribute (see Section 4.4 of PLS 1.0), if a pronunciation lexicon author does not want to distinguish between the two words they could simply be represented as alternative pronunciations within the same <lexeme> element. In the latter case the TTS processor will not be able to distinguish when to apply the first or the second transcription.
In this example the pronunciations of the homograph "bass" are shown.
<?xml version="1.0" encoding="UTF-8"?>
<lexicon version="1.0"
xmlns="http://www.w3.org/2005/01/pronunciation-lexicon"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3.org/2005/01/pronunciation-lexicon
http://www.w3.org/TR/2007/CR-pronunciation-lexicon-20071212/pls.xsd"
alphabet="ipa" xml:lang="en-US">
<lexeme>
<grapheme>bass</grapheme>
<phoneme>bæs</phoneme>
<!-- IPA string is: bæs -->
<phoneme>beɪs</phoneme>
<!-- IPA string is: beɪs -->
</lexeme>
</lexicon>
Note that English contains numerous examples of noun-verb pairs that can be treated either as homographs or as alternative pronunciations, depending on author preference. Two examples are the noun/verb "refuse" and the noun/verb "address".
<?xml version="1.0" encoding="UTF-8"?>
<lexicon version="1.0"
xmlns="http://www.w3.org/2005/01/pronunciation-lexicon"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3.org/2005/01/pronunciation-lexicon
http://www.w3.org/TR/2007/CR-pronunciation-lexicon-20071212/pls.xsd"
xmlns:mypos="http://www.example.org/my_pos_namespace"
alphabet="ipa" xml:lang="en-US">
<lexeme role="mypos:verb">
<grapheme>refuse</grapheme>
<phoneme>rɪˈfjuːz</phoneme>
<!-- IPA string is: "rɪˈfjuːz" -->
</lexeme>
<lexeme role="mypos:noun">
<grapheme>refuse</grapheme>
<phoneme>ˈrɛfjuːs</phoneme>
<!-- IPA string is: "ˈrɛfjuːs" -->
</lexeme>
</lexicon>
Pronunciation by orthography
[edit]For some words and phrases pronunciation can be expressed quickly and conveniently as a sequence of other orthographies. The developer is not required to have linguistic knowledge, but instead makes use of the pronunciations that are already expected to be available. To express pronunciations using other orthographies the <alias> element may be used.
This feature may be very useful to deal with acronym expansion.
<?xml version="1.0" encoding="UTF-8"?>
<lexicon version="1.0"
xmlns="http://www.w3.org/2005/01/pronunciation-lexicon"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3.org/2005/01/pronunciation-lexicon
http://www.w3.org/TR/2007/CR-pronunciation-lexicon-20071212/pls.xsd"
alphabet="ipa" xml:lang="en-US">
<!--
Acronym expansion
-->
<lexeme>
<grapheme>W3C</grapheme>
<alias>World Wide Web Consortium</alias>
</lexeme>
<!--
number representation
-->
<lexeme>
<grapheme>101</grapheme>
<alias>one hundred and one</alias>
</lexeme>
<!--
crude pronunciation mechanism
-->
<lexeme>
<grapheme>Thailand</grapheme>
<alias>tie land</alias>
</lexeme>
<!--
crude pronunciation mechanism and acronym expansion
-->
<lexeme>
<grapheme>BBC 1</grapheme>
<alias>be be sea one</alias>
</lexeme>
</lexicon>
Status and future
[edit]- PLS 1.0 reached the status of W3C Recommendation on 14 October 2008.
See also
[edit]References
[edit]External links
[edit]- PLS Specification (W3C Recommendation)
- W3C Press Release
- SRGS Specification (W3C Recommendation)
- SSML Specification (W3C Recommendation)
- VoiceXML Forum
- France Telecom Orange Labs implementation of PLS 1.0 under the Gnu General Public License version 3
- SourceForge project for Java-based implementation of PLS 1.0