polly.js

// https://www.cronj.com/blog/node-js-text-speech-using-aws-polly/
require('dotenv').config();

var AWS = require('aws-sdk');
var Speaker = require('speaker');
var Stream = require('stream');

var Polly = new AWS.Polly({
	region: 'us-east-1',
	accessKeyId: process.env.AWS_ACCESS_KEY_ID,
	secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY
});

var getPlayer = function() {
	return new Speaker({
		channels: 1,
		bitDepth: 16,
		sampleRate: 16000
	});
}

var params = { OutputFormat: 'pcm', VoiceId: 'Matthew' }

var speak = function(text) {
	params.Text = text;
	Polly.synthesizeSpeech(params, function(err, res) {
		if (err) {
			console.log('err', err)
		} else if (res && res.AudioStream instanceof Buffer) {
			var bufferStream = new Stream.PassThrough()
			bufferStream.end(res.AudioStream)
			bufferStream.pipe(getPlayer());
		}
	})
}

module.exports = { Speak: speak };