Example of SpeechRecognition

var SpeechRecognition = SpeechRecognition || webkitSpeechRecognition
var SpeechGrammarList = SpeechGrammarList || webkitSpeechGrammarList

var recognition = new SpeechRecognition();
var speechRecognitionList = new SpeechGrammarList();

speechRecognitionList.addFromString('#JSGF V1.0;', 1);
recognition.grammars = speechRecognitionList;
recognition.continuous = false;
recognition.lang = 'ru-RU';
recognition.interimResults = false;
recognition.maxAlternatives = 1;

function log(msg) {
    var time = new Date();
    time = ("0" + time.getHours()).slice(-2)   + ":" +
           ("0" + time.getMinutes()).slice(-2) + ":" +
           ("0" + time.getSeconds()).slice(-2);
    chrome.tabs.executeScript({
        code: `console.log("[${time}] ${msg}");`
    });
}

recognition.onresult = function(event) {
    // The SpeechRecognitionEvent results property returns a SpeechRecognitionResultList object
    // The SpeechRecognitionResultList object contains SpeechRecognitionResult objects.
    // It has a getter so it can be accessed like an array
    // The first [0] returns the SpeechRecognitionResult at the last position.
    // Each SpeechRecognitionResult object contains SpeechRecognitionAlternative objects that contain individual results.
    // These also have getters so they can be accessed like arrays.
    // The second [0] returns the SpeechRecognitionAlternative at position 0.
    // We then return the transcript property of the SpeechRecognitionAlternative object
    var transcript = event.results[0][0].transcript;
    var confidence = event.results[0][0].confidence;
    log(`Пользователь сказал: '${transcript}', точность определения: ${confidence}`);
}

recognition.onspeechend = function() {
    log('Запись команды остановлена');
    recognition.stop();
}

recognition.onerror = function(event) {
    log(JSON.stringify(event).replace(/\"/g, "'"));
    log('Произошла ошибка во время записи команды');
}