The Speech Synthesis Api: An Introduction

The Speech Synthesis API: an introduction
by Janeth Kent Date: 05-02-2014 javascript programming webdev api

Today we’re going to focus on the Speech Synthesis API, which uses system libraries to speak, making the Web considerably more accessible.

NOTE: We have to consider that the API is fairly new, so not widely supported. The Speech Synthesis API is supported in Chrome 33+ and Safari. At the time of writing, the stable channel of Chrome is at version 32 so you will need to be running either the Chrome Dev channel or Chrome Canary to see this in action.

The simplest way to use this API is to pass a string to the SpeechSynthesisUtterance object and then use the speak method to have the computer say the string:

var message = new SpeechSynthesisUtterance(‘Hello World!’);  


Now, let's dig a little deeper to see how we can pass the attributes to modify the SpeechSynthesisUtterance object:

  • Text: this is the simplest, and the one we’ve already used.
  • Lang: this attribute will specify the language the synthesis should use (if nothing is specified it falls back on the document default).
  • VoiceURI: specifies the voice and the synthesis service you want to use.
  • Volume: the volume of the speech, from 0 to 1.
  • Rate: the speed at which the voice will speak. Values of 0 to 10 are permissable, but 1 is normal, 2 is double speed, 3 is triple speed and so on, so that 10 would be far too fast.
  • Pitch: the pitch of the voice ranging from 0 to 2.

To demonstrate, we’ll set up a form to determine the text, rate, pitch and volume:

<input type=“text” id=“speech"/><label for=“volume”>Volume</label>  
<input type=“range" max="1" min="0" step="0.1" value="1" id="volume">  
<label for=“rate”>Rate</label><input type=“range" max="5" min="0" step="0.5" value="2.5" id="rate"> 
<label for=“pitch”>Pitch</label><input type="range" max="2" min="0" step="0.1" value="2" id="pitch">  
<button id="talk">Speak</button>

So the first thing we need to do when it comes to the jQuery is to attach a click event to our talk button and then create a new instance of the SpeechSynthesisUtterance:

$("#talk").click(function() {   
var msg = new SpeechSynthesisUtterance();  });

After this is done we need to get the available voices, select the one we want to use and also set the voiceURI:

var voices = window.speechSynthesis.getVoices(); 
msg.voice = voices[10];   msg.voiceURI = 'native';

After this is done we need to move on to the attributes that will rely on user input and for that we will need to get the values of each input in our page using the .val() jQuery method, starting with the volume :

msg.volume = $(‘#volume’).val();

The method is the same for all the other inputs we have:

  msg.rate = $('#rate').val();  
msg.pitch = $('#pitch').val();    
msg.text = $('#speech').val();

Now all we really need to do in order to wrap this little application up is to set the language attribute and in this case I will use plain US English and then use the speechSynthesis.speakmethod to have the computer say the text with the settings we passed:

msg.lang = 'en-US';  speechSynthesis.speak(msg);

And that’s about all we needed to create a simple application using the Speech Synthesis API, this is the full code:

$("#talk").click(function() {    
var msg = new SpeechSynthesisUtterance();    
var voices = window.speechSynthesis.getVoices();   
 msg.voice = voices[10];     
msg.voiceURI = 'native';  
msg.volume = $('#volume').val();  
 msg.rate = $('#rate').val();   
 msg.pitch = $('#pitch').val();    
msg.text = $('#speech').val();    
msg.lang = 'en-US';    
speechSynthesis.speak(msg);  });


And you can also see a demo here.



Original post by Sara Vieira

by Janeth Kent Date: 05-02-2014 javascript programming webdev api hits : 11464  
Janeth Kent

Janeth Kent

Licenciada en Bellas Artes y programadora por pasión. Cuando tengo un rato retoco fotos, edito vídeos y diseño cosas. El resto del tiempo escribo en MA-NO WEB DESIGN END DEVELOPMENT.


Related Posts

Dark Mode on website using CSS and JavaScript

In today’s article we are going to learn how to build pretty much standard these days on the web pages and that is the alternative color mode and switching between…

A Java approach: The Cycles - Introduction

Hello everyone and welcome back! Until now, we have been talking about variables and selection structures, going to consider some of the fundamental aspects of these two concepts. Theoretically, to…

JavaScript: Spread and Rest operators

In today’s article we are going to talk about one of the features of the ES6 version(ECMAScript 2015) of JavaScript which is Spread operator as well as Rest operator. These features…

A Java approach: boolean variables

The previous time, we talked extensively about Boolean variables, trying to outline the main operations that can be carried out at a practical level.  Of all the cases examined, we have…

Why You Should Hire Node.js Developer for Your Backend Development

When developers are building a new website, they mainly focus on both frontend and backend development. The frontend code helps create the interfaces through which the app interacts with the…

A Java approach: condtional structures

Hello everyone and welcome back! The previous times we have introduced the concept of variable, trying to define some basic concepts about it.  However, some situations suggest that the concept of…

Hashmap: Overflow Lists

In this short series of articles we will go to see how it is possible to create the Hashmap data structure in C. In the implementation we're going to use the…

Javascript: what are callbacks and how to use them.

Today we are going to learn about a concept that is widely used in javascript and that is used quite a lot by today's frameworks, libraries, especially NodeJS. This is…

A Java approach: variables - use case

Hello all friends and welcome back! After the introduction made on the variables, we try to analyse some critical issues that may arise in quite common situations. Let's start by analysing…

Introduction to REGEX - Regular Expression

Today we are going to write about Regular Expressions known as regex or shortened  regexp, a very useful concept of using search patterns. Surely you were in a situation when you…

HTTP Cookies: how they work and how to use them

Today we are going to write about the way to store data in a browser, why websites use cookies and how they work in detail. Continue reading to find out how…

5 Remote Careers You Can Start Online in 2020

In 2020, life has moved indoors. School, shopping, entertainment, and work have all moved online to keep up with the fight against COVID-19. And with it came an enormous demand…

We use our own and third-party cookies to improve our services, compile statistical information and analyze your browsing habits. This allows us to personalize the content we offer and to show you advertisements related to your preferences. By clicking "Accept all" you agree to the storage of cookies on your device to improve website navigation, analyse traffic and assist our marketing activities. You can also select "System Cookies Only" to accept only the cookies required for the website to function, or you can select the cookies you wish to activate by clicking on "settings".

Accept All Only sistem cookies Configuration