I'm using chrome Version 55.0.2883.87 m (64-bit) on Windows 10.
The following simple html file reproduces the problem and is extracted from my more complex app. It is supposed to speak the 3 words on page load. It works on MS Edge and Firefox but does not work on chrome. This code was working for me on Chrome no problem a couple weeks back.
<html>
<head>
<script lang="javascript">
window.speechSynthesis.speak(new SpeechSynthesisUtterance("cat"));
window.speechSynthesis.speak(new SpeechSynthesisUtterance("dog"));
window.speechSynthesis.speak(new SpeechSynthesisUtterance("bark"));
</script>
</head>
<body></body>
</html>
speechSynthesis.speak() is no longer allowed without user activation in Google's Chrome web browser since 2018. It violates autoplay policy of Google Chrome. Thus Google Chrome has managed to revoke it's autoplay functionality but you can make use of it by adding a button to make a custom call.
You can visit here to check the status provided by chrome itself also below is the image attached which clearly shows that speechSynthesis.speak() call is prohibited without user's permission.
Link to image
Link to article by Google Chrome