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Re: Comments from PFWG on CSS3 Speech Module

From: Daniel Weck <daniel.weck@gmail.com>
Date: Mon, 17 Oct 2011 08:26:19 +0100
Cc: www-style@w3.org, Bert Bos <bert@w3.org>, List WAI Liaison <wai-liaison@w3.org>, List WAI PF <w3c-wai-pf@w3.org>
Message-Id: <7F80002C-6263-45CF-B33F-50C986B7811F@gmail.com>
To: Janina Sajka <janina@rednote.net>
Hell Janina (et al),

in practice, I don't expect the 'reserve' value to be used much, but there is a use-case nonetheless (as illustrated by the trivial example in the 'voice-family' section). This is currently the only way for authors to override the document language when the intent is to speak some text using a different language accent (e.g. fr-FR versus fr-CA). As usual, authors have the responsibility to produce content that is coherent, but this applies to any CSS feature, not just speech (e.g. dark grey text on black background is inherently bad authoring practice).

Let's also bare in mind that in a future version (i.e. Level 4+) of the CSS Speech Module, authors will probably be able to explicitly specify a list of preferred language/accent candidates (right now, only the document/markup language is considered by the voice selection algorithm). This is a powerful feature introduced in SSML 1.1, which unfortunately cannot make its way into Level 3 of CSS Speech due to normative dependencies on the BCP47 specifications, and because of the required conformance requirements on speech synthesizers.

I hope this clarifies the matter. Please let us know whether this is a satisfactory response.
Many thanks!
Regards, Daniel

On 11 Oct 2011, at 20:25, Janina Sajka wrote:

> 6.)	voice-family: preserve;
> 
> Quoting from the editor's draft: 
> 
>> regardless of any potential language change within the content markup
> 
> This property value appears short-sighted, as most TTS voices are not only intended for a particular language, but are also mostly incapable of producing speech when confronted with characters outside its intended range of unicode characters. For example, it is highly unlikely that a Chinese TTS voice will be able to pronounce English in an understandable way (for anything other than very common words such as "okay") , and it's even less likely that a French TTS voice would be able to speak any words in Japanese. It seems this property value is only beneficial to force Western language TTS voices to mispronounce other Western languages, which is a feature of very little utility.
> 
> PFWG wishes to emphasize its strong preference that lang declarations,
> explicitly including in line lang attributes, be processed using language
> appropriate phonemes and pronunciation rules. Several screen readers do so
> today. All speech generators should be expressly encouraged to do so.
> 
> PFWG further suggests that there be a way to specify an accent or locale setting.
Received on Monday, 17 October 2011 07:27:12 GMT

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