Nawar Halabi has very kindly provided an introductory video of the Arabic version of ATbar and we have uploaded it to YouTube.
YouTube video overview of ATbar in Arabic
Nawar has also been testing the Arabic version as part of our maintenance programme. We have found some issues with Arabic mis-aligned text at times and there are occasions when the CSS of the website needs to be isolated from the toolbar. Otherwise all the plugins appear to have worked well in the last few months.
Testing the Arabic dictionary
Testing the spell checker, text to speech and word prediction.
Where failures were reported these were double checked and found to be due to the word not being a partial word or not being in the dictionaries – usually due to an English speaking person trying to cut and past Arabic words!
Magnus has added an extended Arabic dictionary to our spell checker which has resulted in better error correction. The size of this new dictionary is twenty times larger than the one used originally building on the original Aspell dictionary. We are also able to supplement the database with additional words.
Alaa has been testing the checker and noticed an error on our web page that we use for trying the toolbar. This time the words offered as alternatives made sense and could be used when she was making mistakes.
We now have a database that records the word that has been misspelled, saves the error alongside the word that has been chosen from the correction list or notes the fact that the user has ignored the offered words. The database handles all languages but those words in Arabic are appear incomprehensible to readers due to the UTF-8 coding.
We have set up a series of YouTube videos that include:
Text resizing, font style changes and line spacing. This video has no audio but shows how a user can select the magnifier on the toolbar to enlarge text without resizing the graphics – this tends to allow for more readable text when compared to zooming using the browser Ctrl+ which also enlarges the graphics. However, this feature does not work when Flash has been used within a webpage or fonts have fixed sizes or styles. The same applies to increased line spacing which is also demonstrated.
The second video demonstrates how the A.I.Type word prediction works as well as spell checking when writing a blog using WordPress. Use the HTML mode when working in the edit box rather than the Visual mode and then you will also be able to use the text to speech to aid proof reading.
Seb has enabled the AIType word prediciton with keyboard access and text to speech for simple text boxes in his recent updates to the toolbar for both Arabic and English.
The Word prediction button needs to be selected before entering text. It is possible to use the ‘esc’key to ignore a prediction and close the dialog box or use Ctrl+Alt and the word position as a number to insert the required word.
Word Prediction in WordPress
We have found that the prediction and text to speech work with HTML views of text boxes in WordPress and Blogger but not the Visual mode which overrides the ATbar.
The text needs to be highlighted before the text to speech button is selected. There may be a pause before you hear the speech.
Over the summer the team have been investigating the issues around TTS in Arabic and Edrees Abdu Alkinani has completed his MSc report which has made interesting reading as it summarises many of the findings. It was noted that Arabic TTS synthesis did not have the early successes of European languages due to the limitations in Natural Language Processing (NLP) and the complexities of using diacritics as substitutes for vowel combinations. However, with the advances in Natural Language Processing (NLP) and Digital Signal Processing (DSP) plus automatic diacrtizers progress is being developed progress has been made in the commercial world where there are now several attractive Arabic synthesised voices as will be seen in an evaluation to follow.
Issue No 1 – Lack of diacritics on web pages.
The Learning Resource - Arabic language
English speakers may wonder at the reasons for the difficulties with Arabic TTS, but it does not take more than a cursory glance at the written language to understand that having 14 different diacritic marks with 34 phonemes, 28 of which are consonants, and only six vowels that the combinations may cause TTS problems. As Eedris pointed out… ” كُتُبْ ” means books and ” كَتَبَ ” means wrote – the only difference you will notice is the type of marks used above the letters.
TEFL world wiki - English vowel sounds
This is compared to the English basic 12 vowel sounds with no accents or diacritics even though we may complain about our odd pronunciation of some written words – rough, cough, though, thorough and through – at least some of the letters are different and we cannot leave any out. Yet this is what is happening with written Arabic on the web – the diacritics are being left out….. Number one problem for a text to speech engine.
Issue No 2 – The differences between the way the TTS is developed and the resulting output.
Research has shown that although there are now a few text to speech engines they are commercial and even these vary in quality. The MBROLA project links to work carried out in the open source world, but at present it has been impossible to achieve success with the code offered in the various repositories for evaluation purposes. However, Eedris has supplied the team with these comments based on the demonstrators offered by the various organisations and companies.
MBROLA project MBROLA has two Arabic voices as a recorded audio file. The speed of speech is slow, and the quality poor. Moreover, the pronunciation is hard to understand – even for a an Arabic speaker. The stress pattern is often incorrect and the distinction between words unclear. The most difficult words to understand have letters like, “ أ” ‘A’, “ ض” ‘th’, “ ل” ‘L’.
Acapela Group Acapela offers two good quality male and female voices. The pronunciation for words with and without diacritic marks is understandable, with accurate stress patterns. There are three letters which appear to cause some difficulty “ ج” ‘j’, “ ا’ ‘a’, “ ك” ‘k’. The pronunciation of numbers in all situations is good.
Nuance Vocalizer Nuance provide a very clear male voice with clear pronunciation. The only problem is that the system produces speech without taking into account diacritics. Words which have letters like “ ق” ‘q’, “ ش” ‘sh’, and “ ض” ‘th’ may cause problems but the speed of speech used in the online demo is good. Numbers are not clearly enunciated due to the lack of diacritics.
Loquendo Loquendo offer a recording of a male and female voice on their site as the Arabic voice has only be available since October 2010. The system has good sound quality clear speech. The example on the website has diacritic marks but as it is a small sample it is hard to judge the overall quality but it appears to be good.
Issue No 3 – Further Development of eSpeak with Arabic.
The current version of MBROLA does not appear to run with the arabic voice files and there seem to be very few people who have had success. So this is work in progress…
There are several spell checkers available as open source applications and much has been said about the quality of their output in English but there appears to be very little research when linked to the Arabic language. However, Hunspell is used with many word processing packages.
Seb has succeeded in getting it to work with ATbar vers 2 which means that the Kit version is now almost in beta and there is the beginnings of an Arabic spell checker.