Inside Macintosh: Sound /

Chapter 4 - Speech Manager

This chapter describes the Speech Manager, the part of the Macintosh system software that provides a standardized method for Macintosh applications to generate synthesized speech.

You need to read this chapter if you want your application to be able to generate speech. For example, you may want your application to incorporate the capability to speak its dialog box messages to the user. A word-processing application might use the Speech Manager to implement a command that speaks a selected section of a document to the user. A multimedia application might use the Speech Manager to provide a narration of a QuickTime movie instead of including sampled-sound data on a movie track. Because sound samples can take up large amounts of room on disk, using text in place of sampled sound is extremely efficient.

If you are developing an application that needs only to generate speech from strings, then the information on speech contained in the chapter "Introduction to Sound on the Macintosh" in this book might be sufficient. If, however, you need to be able to manipulate the speech output or customize it to make it easier for your users to understand, you should read this chapter.

The Speech Manager is not available in all system software versions. It was introduced with the Macintosh computers with audio visual capabilities in the summer of 1993. It will continue to be incorporated into future versions of system software. You should use the Gestalt function to ensure that the speech services you need are available before calling them. See the discussion in the section "Checking for Speech Manager Capabilities" beginning on page 4-12 for details.

The Speech Manager and the Sound Manager adopt many of the same metaphors in the processes of sound production and speech generation. You should be aware that the Speech Manager's approach often differs in subtle but important ways from that of the Sound Manager. Reading the chapter "Sound Manager" in this book might help you to learn to use the Speech Manager, but it is not required.

Also, while the Speech Manager uses the Sound Manager, your application should not attempt to directly access any Sound Manager data structures used by the Speech Manager. Because the Speech Manager is likely to be a rapidly evolving portion of system software, relying on Speech Manager data structures not explicitly documented in this chapter is likely to pose compatibility problems for your application.

This chapter begins with an introduction to the speech generation process and then discusses how you can

• check for the availability of the Speech Manager
• create and dispose of speech channels
• generate speech with different voices
• obtain information about and change speech channel settings
• start and stop speech production
• synchronize speech production with other activities by using callback procedures
• embed Speech Manager commands within text to make it more understandable
• convert text into phonemes and allow the user to enter phonetic text directly
• create, install, and manipulate customized pronunciation dictionaries

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Chapter Contents

About the Speech Manager

Voices

Speech Attributes

Speech Channels

Callback Routines

Using the Speech Manager

Checking for Speech Manager Capabilities

Creating, Using, and Disposing of a Speech Channel

Working With Different Voices

Adjusting Speech Attributes

Pausing Speech

Implementing Callback Procedures

Writing Embedded Speech Commands

Embedded Command Delimiters

Syntax of Embedded Speech Commands

Examples of Embedded Speech Commands

Phonemic Representation of Speech

Phonemic Symbols

Prosodic Control Symbols

Including Pronunciation Dictionaries

Speech Manager Reference

Constants

Speech Information Selectors

Data Structures

Voice Specification Records

Voice Description Records

Voice File Information Records

Speech Status Information Records

Speech Error Information Records

Speech Version Information Records

Phoneme Information Records

Phoneme Descriptor Records

Speech Extension Data Records

Delimiter Information Records

Speech Manager Routines

Starting, Stopping, and Pausing Speech

Obtaining Information About Voices

Managing Speech Channels

Obtaining Information About Speech

Changing Speech Attributes

Converting Text To Phonemes

Installing a Pronunciation Dictionary

Application-Defined Routines

Text-Done Callback Procedure

Speech-Done Callback Procedure

Synchronization Callback Procedure

Error Callback Procedure

Phoneme Callback Procedure

Word Callback Procedure

Resources

The Pronunciation Dictionary Resource

Summary of the Speech Manager

Pascal Summary

Constants

Data Structures

Speech Manager Routines

Application-Defined Routines

C Summary

Constants

Data Types

Speech Manager Routines

Application-Defined Routines

Assembly-Language Information

Data Structures

Trap Macros

Result Codes