Voice API Programming Guide — June 2005 147
13
13.Global Tone Detection and
Generation, and Cadenced Tone Generation
This chapter discusses global tone detection (GTD), global tone generation (GTG), and cadenced
tone generation:
Global Tone Detection (GTD). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Global Tone Generation (GTG). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Cadenced Tone Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

13.1 Global Tone Detection (GTD)

Global tone detection (GTD) is described in the following sections:
Overview of Global Tone Detection
Global Tone Detection on DM3 Boards versus Springware Boards
Defining Global Tone Detection Tones
Building Tone Templates
Working with Tone Templates
Retrieving Tone Events
Setting GTD Tones as Termination Conditions
Maximum Amount of Memory for Tone Templates
Estimating Memory
Guidelines for Creating User-Defined Tones
Global Tone Detection Application

13.1.1 Overview of Global Tone Detection

Global tone detection (GTD) allows you to define single or dual frequency tones for detection. The
characteristics of a tone are defined in a GTD tone template. A tone template contains parameters
that allow you to assign frequency bounds and cadence components. GTD can detect single and
dual frequency tones by comparing all incoming sounds to the GTD tone templates. Global tone
detection and GTD tones are also known as user-defined tone detection and user-defined tones.
The typical use of global tone detection is to detect single and dual frequency tones other than
those automatically provided with the voice software. This includes tones outside the standard