SAPI 5.1
SAPI text-to-speech (TTS) extensible markup language (XML) tags fall into several
categories.
SAPI TTS XML supports five tags that control the state of the current voice:
Volume, Rate, Pitch, Emph, and Spell.
The Volume tag controls the volume of a voice. The tag can be empty, in
which case it applies to all subsequent text, or it can have content, in which
case it only applies to that content.
The Volume tag has one required attribute: Level. The value of this
attribute should be an integer between zero and one hundred. Values outside of
this range will be truncated.
<volume level="50">
This text should be spoken at volume level fifty.
<volume level="100">
This text should be spoken at volume level one hundred.
</volume>
</volume>
<volume level="80"/>
All text which follows should be spoken at volume level eighty.
One hundred represents the default volume of a voice. Lower values represent
percentages of this default. That is, 50 corresponds to 50% of full volume.
Values specified using the Volume tag will be combined with values specified
programmatically (using ISpVoice::SetVolume). For example, if you combine a
SetVolume( 50 ) call with a <volume level="50"> tag, the volume
of the voice should be 25% of its full volume.
The Rate tag controls the rate of a voice. The tag can be empty, in which
case it applies to all subsequent text, or it can have content, in which case
it only applies to that content.
The Rate tag has two attributes, Speed and AbsSpeed, one of which must be
present. The value of both of these attributes should be an integer between
negative ten and ten. Values outside of this range may be truncated by the
engine (but are not truncated by SAPI). The AbsSpeed attribute controls the
absolute rate of the voice, so a value of ten always corresponds to a value of
ten, a value of five always corresponds to a value of five.
<rate absspeed="5">
This text should be spoken at rate five.
<rate absspeed="-5">
This text should be spoken at rate negative five.
</rate>
</rate>
<rate absspeed="10"/>
All text which follows should be spoken at rate ten.
The Speed attribute controls the relative rate of the voice. The absolute
value is found by adding each Speed to the current absolute value.
<rate speed="5">
This text should be spoken at rate five.
<rate speed="-5">
This text should be spoken at rate zero.
</rate>
</rate>
Zero represents the default rate of a voice, with positive values being
faster and negative values being slower. Values specified using the Rate tag
will be combined with values specified programmatically (using
ISpVoice::SetRate).
The Pitch tag controls the pitch of a voice. The tag can be empty, in which
case it applies to all subsequent text, or it can have content, in which case
it only applies to that content.
The Pitch tag has two attributes, Middle and AbsMiddle, one of which must be
present. The value of both of these attributes should be an integer between
negative ten and ten. Values outside of this range may be truncated by the
engine (but are not truncated by SAPI).
The AbsMiddle attribute controls the absolute pitch of the voice, so a value
of ten always corresponds to a value of ten, a value of five always corresponds
to a value of five.
<pitch absmiddle="5">
This text should be spoken at pitch five.
<pitch absmiddle="-5">
This text should be spoken at pitch negative five.
</pitch>
</pitch>
<pitch absmiddle="10"/>
All text which follows should be spoken at pitch ten.
The Middle attribute controls the relative pitch of the voice. The absolute
value is found by adding each Middle to the current absolute value.
<pitch middle="5">
This text should be spoken at pitch five.
<pitch middle="-5">
This text should be spoken at pitch zero.
</pitch>
</pitch>
Zero represents the default middle pitch for a voice, with positive values
being higher and negative values being lower.
The Emph tag instructs the voice to emphasize a word or section of text. The
Emph tag cannot be empty. The following word should be emphasized.
<emph> boo </emph>!
The method of emphasis may vary from voice to voice.
The Spell tag forces the voice to spell out all text, rather than using its
default word and sentence breaking rules, normalization rules, and so forth.
All characters should be expanded to corresponding words (including
punctuation, numbers, and so forth). The Spell tag cannot be empty.
<spell>
These words should be spelled out.
</spell>
These words should not be spelled out.
Three tags are supported that applications the ability to insert items
directly at some level: Silence, Pron, and Bookmark.
The Silence tag inserts a specified number of milliseconds of silence into
the output audio stream. This tag must be empty, and must have one attribute,
Msec.
Five hundred milliseconds of silence <silence msec="500"/> just occurred.
The Pron tag inserts a specified pronunciation. The voice will process the sequence
of phonemes exactly as they are specified. This tag can be empty, or it can
have content. If it does have content, it will be interpreted as providing the
pronunciation for the enclosed text. That is, the enclosed text will not be
processed as it normally would be.
The Pron tag has one attribute, Sym, whose value is a string of white space
separated phonemes.
<pron sym="h eh 1 l ow & w er 1 l d "/>
<pron sym="h eh 1 l ow & w er 1 l d"> hello world </pron>
The Bookmark tag inserts a bookmark event into the output audio stream. Use
this event to signal the application when the audio corresponding to the text
at the Bookmark tag has been reached. The Bookmark tag must be empty.
The Bookmark tag has one attribute, Mark, whose value is a string. This
value can then be used to differentiate between bookmark events (each of which
will contain the string value from their corresponding tag).
The application will receive an event here,
<bookmark mark="bookmark_one"/>
and another one here
<bookmark mark="bookmark_two"/>
Two tags provide context to the current voice: PartOfSp and Context. Those
tags enable the voice to determine how to deal with the text it is processing.
With both of these tags, the extent to which voices use the context may vary.
The PartOfSp tag provides the voice with the part of speech of the enclosed
word(s). Use this tag to enable the voice to pronounce a word with multiple
pronunciations correctly depending on its part of speech. The PartOfSp tag
cannot be empty.
The PartOfSp tag has one attribute, Part, which takes a string corresponding
to a SAPI part of speech as its attribute. Only SAPI defined parts of speech
are supported - "Unknown", "Noun", "Verb",
"Modifier", "Function", "Interjection".
<partofsp part="noun"> A </partofsp> is the first letter of the alphabet.
Did you <partofsp part="verb"> record </partofsp> that <partofsp part="noun"> record </partofsp>?
The Context tag provides the voice with information which the voice may then
use to determine how to normalize special items, like dates, numbers, and
currency. Use this tag to enable the voice to distinguish between confusable
date formats (see the example, below). The Context tag cannot be empty.
The Context tag has one attribute, Id, which takes a string corresponding to
the context of the enclosed text. Several contexts are defined by SAPI and are
more likely to be recognized by SAPI compliant voices, but any string may be
used. See documentation for a particular voice for more details.
<context id="date_mdy"> 03/04/01 </context> should be March fourth, two thousand one.
<context id="date_dmy"> 03/04/01 </context> should be April third, two thousand one.
<context id="date_ymd"> 03/04/01 </context> should be April first, two thousand four.
There are two tags which can be used (potentially) to change the current
voice: Voice and Lang.
The Voice tag selects a voice based on its attributes, Age, Gender,
Language, Name, Vendor, and VendorPreferred. The tag can be empty, in which
case it changes the voice for all subsequent text, or it can have content, in
which case it only changes the voice for that content.
The Voice tag has two attributes: Required and Optional. These correspond
exactly to the required and optional attributes parameters to ISpObjectTokenCategory_EnumerateTokens
and SpFindBestToken functions. The
selected voice follows exactly the same rules as the latter of these two
functions. That is, all the required attributes are present, and more optional
attributes are present than with the other installed voices (if several voices
have equal numbers of optional attributes one is selected at random). See Object Tokens and Registry Settings
for more details.
In addition, the attributes of the current voice are always added as
optional attributes when the Voice tag is used. This means that, a voice which
is more similar to the current voice will be selected over one which is less
similar.
If no voice is found that matches all of the required attributes, no voice
change will occur.
The default voice should speak this sentence.
<voice required="Gender=Female;Age!=Child">
A female non-child should speak this sentence, if one exists.
<voice required="Age=Teen">
A teen should speak this sentence - if a female, non-child teen is present, she will be selected over a male teen, for example.
</voice>
</voice>
The Lang tag selects a voice based solely on its Language attribute. The tag
can be empty, in which case it changes the voice for all subsequent text; or it
can have content, in which case it only changes the voice for that content.
The Lang tag has one attribute, LangId. This attribute should be a LANGID,
such as 409 (U.S. English) or 411 (Japanese). Note that these numbers are
hexadecimal, but without the typical "0x".
The Lang tag is a shortened version of the Voice tag with the Required
attribute containing "Language=xxx". So the following examples should
produce exactly the same results:
<voice required="Language=409">
A U.S. English voice should speak this.
</voice>
<lang langid="409">
A U.S. English voice should speak this.
</lang>
An alternative to using the <P> tag with the DISP and PRON attributes
is to use custom pronunciation. Using custom pronunciation, tags in the form of
the following.
<P DISP="disp" PRON="pron">word</P>
can be written as
<P>/disp/word/pron;</P>
More specifically, if you want to recognize the word hello only when it is
pronounced as ah and display greeting when recognized, you would normally use
something like the following.
<P DISP="greeting" PRON="ah">hello</P>
Using custom pronunciation, the above would translate to the following.
<P>/greeting/hello/ah;</P>