W3C Workshop, Beijing, 2nd of November 2005 An extension to the SSML for diacritics auto-completion R&D Centre Vocal Services Section

2 Regarding: Diacritics auto-completion Plan of the presentation ●The nature of the problem ●Similarities among other languages ●Possible solutions ●Discussion

3 Regarding: Diacritics auto-completion Diacritics diacritical mark or diacritic, sometimes called an accent mark, is a mark added to a letter to alter a word's pronunciation or to distinguish between similar words. Example: Polish letters with diacritics: Ą ą Ć ć Ę ę Ł ł Ń ń Ó ó Ś ś Ź ź Ż ż ●Polish alphabet contains 35 letters=26 basic + 9 with diacritics ●Different pronunciation from letters without diacritics ●Included in ISO , UNICODE, CP-1250, DOS 852… ●Not included in US ASCII 7-bit codepage ?

4 Regarding: Diacritics auto-completion Why Polish diacritics sometimes disappear? ●No possibility to obtain while typing o Application / hardware does not support non US-ASCII characters o Improper regional settings in OS or firmware ●The codepages hell o All the codepages differs from each other o Unicode (utf-8) is still not very popular ●Pruned on WWW - SMS gateways ●A little bit hard to type o As a combination Alt gr+ on a PC keyboard („Polish programmer” variant of US keyboard) o As the 5th or further letter on a key of mobile phone keypad (key 2 sequence=„ABC2ĄĆ”

5 Regarding: Diacritics auto-completion quasi-Polish text (without diacritics) ●Is not orthographically correct ●Is not up to netiquette ●Is not Polish (in fact) ●Can not be transformed into Polish with simple substitution rules ●Speech synthesised from this text may be incomprehensible …but: ●Sometimes it is the only possibility to represent text ●Is easier to write = can be written faster ●Can be quite easily read by human as if it was written correctly (because of nature of „human reading device”) thus: is widespread in Polish s, SMSes, news posts and chats

6 Regarding: Diacritics auto-completion Examples slonce –> słońce ( Eng. the Sun) - unambiguous mapping maki –> maki ( Eng. poppies Nominative, plural ) or mąki ( Eng. flour Genitive, singular ) Question: add a diacritic or not ? zeby –> zęby ( Eng. teeth Nominative, plural ) or żeby ( Eng. in order that ) Question: Where to add a diacritic ?

7 Regarding: Diacritics auto-completion Other languages ●Czech, Slovak ●Problem with diacritics is very similar to Polish ●German ●Umlaut „ ä ü ö ” and sharp „s” = β ●Russian ●Volapuk encoding – informal romanization used in SMSes ●e.g.: „Ж” = „}” + „|” + „{” ●French ●Accents strongly affecting pronunciation, e.g.: „è” „é” „ê” ●Other diacritics: „ë” „ï” „ô” „û” ●… and many other

8 Regarding: Diacritics auto-completion How to classify the problem? ●a new dialect? ●an alternative spelling (context dependent orthography)? ●an erroneous text that requires correction (jargon)?

9 Regarding: Diacritics auto-completion Example: Multi-channel access to Instant Messaging user text Visually impaired user Message IM Server IM Server SMS gateway Speech Synthesis Text Processing Mobile user Home IM user From: chris Date: 2nd Nov 05 Time: 10h15 Msg: Correct text Text without diacritics

10 Regarding: Diacritics auto-completion Variant 1: correction by IM server ●Do everything on server side -SSML content developer takes care about correct spelling in text send to TTS -Text processing (correction software) is tight to the IM Server vendor which may lead to proprietary solutions +TTS is given correct text so has no problem to render it No need for data exchange format standardization Message in SSML 1.0 IM Server IM Server Speech Synthesis Built-in Text Processing TTS engine Proprietary Text Processing Rules

11 Regarding: Diacritics auto-completion Variant 2: correction by TTS engine ●IM does not do anything – lets the TTS engine render the text +No additional work of SSML content developer required -TTS must recognize scope of the quasi-correct part of text (no tags in current SSML) -TTS must complete diacritics to correctly pronounce text Message in SSML 1.0 IM Server IM Server Speech Synthesis Built-in Text Processing TTS engine Proprietary Text Processing Rules

12 Regarding: Diacritics auto-completion Variant 3 – use external lexicons ●Use special lexicon file to properly render text: +Quite simple and easy for SSML developer -Lexicon affects the whole file: correct and quasi-correct parts -No context dependent rules in PLS (req. 7.3) -No prefix/suffix morphological rules in PLS (req. 7.2) -The lack of diacritics is not a pronunciation exception but a spelling error Message in SSML 1.0 IM Server IM Server Speech Synthesis Lexicon-based built-in Text Processing TTS engine Lexicons in PLS 1.0 Text Processing Lexicons

13 Regarding: Diacritics auto-completion Recommendation ●Use separate correction unit for jargon (external) ●Enclose quasi-correct text with tags +Still easy for SSML developers +Text Correction software knows which part of text should be specifically pre- processed +For diacritics completion an external program can be used +For simpler cases, just dedicated lexicon can be used -SSML needs to be extended Message in enhanced SSML 1.0 IM Server IM Server Speech Synthesis Lexicon-based built-in Text Processing TTS engine Lexicons in PLS 1.0 Text Processing Lexicons Jargon Text Correction

14 Regarding: Diacritics auto-completion Example of SSML document (jsp)... User writes: The message has been sent : at

15 Regarding: Diacritics auto-completion Another example... User writes: The message has been sent : at

16 Regarding: Diacritics auto-completion Conclusions ●In modern communication services people use specific language, frequently not conforming to orthographic rules (e.g. without diacritics) ●Applying standard phonetization rules to erroneous text may result in incomprehensible speech ●TTS for best rendering results should have complete information about the text ●One SSML document can have both correct and erroneous text; there is a need to mark it ●Correcting erroneous text can be context and application dependent

17 Regarding: Diacritics auto-completion Questions and doubts 1.How many types of erroneous input should we consider? 2.How to handle jargon evolution? 3.How does input device affect the text? 4.New interpret-as value or a new tag? 5.Scope and structure of the new tag (if applicable)? 6.Will future TTS be a software composed of complex text processor and acoustic synthesis engine, or will we have a possibility to freely choose these modules from different vendors?

18 Regarding: Diacritics auto-completion Dziękujemy Thank you

19 Regarding: Diacritics auto-completion Prepared by: Name:Przemyslaw Zdroik Division:Vocal Services Secion Department: TP S.A. Research and Development Centre Phone#: (+ 48) Name:Krzysztof Majewski Division:Vocal Services Section Department: TP S.A. Research and Development Centre Phone#: (+ 48)