このコードを実行すると、入力がオーディオ(マイク)として取得され、オーディオ再生よりもテキストに変換されます。
<!doctype HTML>
<head>
<title>MY Echo</title>
<script src="http://code.responsivevoice.org/responsivevoice.js"></script>
<link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.6.1/css/font-awesome.min.css" />
<style type="text/css">
    body {
        font-family: verdana;
    }
    #result {
        height: 100px;
        border: 1px solid #ccc;
        padding: 10px;
        box-shadow: 0 0 10px 0 #bbb;
        margin-bottom: 30px;
        font-size: 14px;
        line-height: 25px;
    }
    button {
        font-size: 20px;
        position: relative;
        left: 50%;
    }
</style>
    JSの音声からテキストへのコンバーターvarr= document.getElementById('result');
    function startConverting() {
        if ('webkitSpeechRecognition' in window) {
            var speechRecognizer = new webkitSpeechRecognition();
            speechRecognizer.continuous = true;
            speechRecognizer.interimResults = true;
            speechRecognizer.lang = 'en-IN';
            speechRecognizer.start();
            var finalTranscripts = '';
            speechRecognizer.onresult = function(event) {
                var interimTranscripts = '';
                for (var i = event.resultIndex; i < event.results.length; i++) {
                    var transcript = event.results[i][0].transcript;
                    transcript.replace("\n", "<br>");
                    if (event.results[i].isFinal) {
                        finalTranscripts += transcript;
                        var speechresult = finalTranscripts;
                        console.log(speechresult);
                        if (speechresult) {
                            responsiveVoice.speak(speechresult, "UK English Female", {
                                pitch: 1
                            }, {
                                rate: 1
                            });
                        }
                    } else {
                        interimTranscripts += transcript;
                    }
                }
                r.innerHTML = finalTranscripts + '<span style="color:#999">' + interimTranscripts + '</span>';
            };
            speechRecognizer.onerror = function(event) {};
        } else {
            r.innerHTML = 'Your browser is not supported. If google chrome, please upgrade!';
        }
    }
</script>
</body>
</html>