Speech Synthesis API Volume, Rate, and Pitch don't work

Question

Long story short, Speech Synthesis volume, rate, and pitch don't work. Is there anyone else having this issue and know how to resolve it, or am I alone?

Long story longer:

For me, Speech Synthesis volume, rate, and pitch don't work. Here is my speech function:

function speak(message, voice, callback, volume, rate, pitch, start, lang) {
    if (speech) {
        window.speechSynthesis.onvoiceschanged = function() {
            voices = window.speechSynthesis.getVoices();
            var msg = new SpeechSynthesisUtterance();
            msg.voice = (typeof voice != "undefined" && voice != 0) ? voices[voice] : voices[0]; // Note: some voices don't support altering params
            msg.volume = (typeof volume != "undefined" && volume != 0) ? volume : 1; // 0 to 1
            msg.rate = (typeof rate != "undefined" && rate != 0) ? rate : 1; // 0.1 to 10
            msg.pitch = (typeof pitch != "undefined" && pitch != 0) ? pitch : 2; //0 to 2
            msg.text = message;
            msg.lang = (typeof lang != "undefined" && lang != 0) ? lang : "en-US";

            msg.onstart = function(event) {
                if (typeof start != "undefined" && start != 0) {
                    start(event);
                }
            }

            msg.onend = function(event) {
                console.log(event.elapsedTime);
                if (typeof callback != "undefined" && callback != 0) {
                    callback(event);
                }
            };

            speechSynthesis.speak(msg);
        };
    }
}

However, when I call speak("Hello", 0, 0, 0.1) it outputs the exact same thing as speak("Hello"). I want to make it output the same thing but softer.

I am currently following http://updates.html5rocks.com/2014/01/Web-apps-that-talk---Introduction-to-the-Speech-Synthesis-API .

1.21 gigawatts · Answer 1 · 2018-05-22T02:02:56.837

2

This is more of a comment but it could be a typo.

It looks like Speech Synthesis class has a rate property as well.

Be sure to set it on the utterance and not the speech synthesis object.

Incorrect:

speechSynthesis.rate = 2;
speechSynthesis.speak(utterance);

Correct:

utterance.rate = 2;
speechSynthesis.speak(utterance);

edited May 22 '18 at 02:02

answered May 22 '18 at 00:40

1.21 gigawatts

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score 1 · Answer 2 · answered Dec 27 '14 at 20:14

1

For some reason, the parameters will work if you change the language to en-EN.

answered Dec 27 '14 at 20:14

John Lee

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score 0 · Answer 3 · answered Jan 29 '15 at 18:37

0

From what I am seeing, setting these parameters only has an effect when the voice is from a local service.

As you noted, this is probably a case of not all voices supporting the ability to set parameters.

answered Jan 29 '15 at 18:37

Sarah Elan

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score 0 · Answer 4 · answered Apr 07 '15 at 02:10

I am trying to do the same thing too. But i managed to make it work by adding a fullstop where I want it to slow down. I know this is not the right way to do it but it is kind of working for me

var u = new SpeechSynthesisUtterance();
        u.text = 'Welcome to Handy Mandy. Lets Get Started. Say Handy Mandy.';
        //u.lang = 'en-US';
        //u.rate = 10;
        //u.onend = function(event) { alert('Finished in ' + event.elapsedTime + ' seconds.'); }
        speechSynthesis.speak(u);

Before this it

Speech Synthesis API Volume, Rate, and Pitch don't work

4 Answers4