# ALTextToSpeech ¶

NAOqi Audio - Overview | API | Tutorial

## What it does ¶

The ALTextToSpeech module allows the robot to speak. It sends commands to a text-to-speech engine, and authorizes also voice customization. The result of the synthesis is sent to the robot’s loudspeakers.

## How it works ¶

### Speech engines ¶

ALTextToSpeech is based on speech synthesizers - or speech engines.

According to the selected language, a specific engine is used:

Pepper NAO
Japanese microAITalk engine, provided by AI, Inc . microAITalk engine, provided by AI, Inc .
Other languages NUANCE ACAPELA or NUANCE

Note : the engine used is indicated in the description of the package.

## Customization ¶

### Using parameters ¶

The output audio stream can be modified.

For example, these effects are available:

• pitch shifting effect modifies the initial pitch of the voice,
• double voice effect produces a “delay/echo” effect on the main voice.

Additional parameters are available for microAITalk engine.

Further information can be found here:  ALTextToSpeechProxy::setParameter 

### Using tags ¶

To add some expressiveness when the robot speaks, it is highly recommended to use “tags” in your text. Tags, allows you to change, in the middle of a sentence, the pitch, the speed, the volume of a word, or add pauses between words, change the emphase of word.

For further details, see: Using tags for voice tuning .

## Getting Started ¶

The easiest way to get started with ALTextToSpeech is to use the Say Choregraphe box.

### Testing on a real or a virtual robot ¶

ACAPELA , microAITalk and Nuance engines are only available on the real robot.

When using a virtual robot, said text can be visualized in Choregraphe Robot View and Dialog panel .