
2-11
2—SOFTWARE
ISD-SR3000
ISD
A good combination of sentence quality and memory space is achieved if you take the “com-
pact” approach, and extend it to solve pronunciation problems. For example, the word twenty
is pronounced differently when used in the sentences
You have twenty names
and
You have
twenty-two names
. To solve this problem, words that are pronounced differently should be re-
corded more than once, each in the correct pronunciation.
VOCABULARY RECORDING
When recording vocabulary words, there is a compromise between space and quality. The
words should be recorded and saved in a compressed form, and you should use the best voice
compression for that purpose. However, lower compression rates do affect the voice quality.
Another issue to consider is the difference in voice quality between synthesized and recorded
audio (e.g. between stored audio prompts and recorded names). It is more pleasant for the hu-
man ear to hear both messages with the same sound quality.
VOCABULARY ACCESS
Sometimes compactness and high quality are not enough. There should be a simple and flex-
ible interface to access the vocabulary elements. Not just the vocabulary, but the code to ac-
cess the vocabulary should be compact.
When designing for a multi-lingual environment, there are even more issues to consider. Each
vocabulary should be able to handle language-specific structures and designed in a coopera-
tive way with the other vocabularies so that the code to access each vocabulary is the same.
When you use the command to synthesize the sentence
Monday. 12:30
P
.
M
.,
you should not
care in what language the message is played back.
2.8.3
This section describes the basic concept of an IVS vocabulary, its components, and the rela-
tionships between them.
IVS VOCABULARY COMPONENTS
BASIC CONCEPTS
An IVS vocabulary consists of words, sentences, and special codes that control the behavior of
the algorithm which ISD-SR3000 processor uses to synthesize sentences.
WORD TABLE
The words are the basic units in the vocabulary. Create synthesized sentences by combining
words in the vocabulary. Each word in the vocabulary is given an index which identifies it in the
word table.
Note that, depending on the language structures and sentences synthesized, you may need to
record some words more than once in the vocabulary. For example, if you synthesize the sen-