add support for deepgram STT

lib/utils/speech-utils.js

@@ -2,6 +2,7 @@ const ttsGoogle = require('@google-cloud/text-to-speech');
 const sttGoogle = require('@google-cloud/speech').v1p1beta1;
 const Polly = require('aws-sdk/clients/polly');
 const AWS = require('aws-sdk');
+const { Deepgram } = require('@deepgram/sdk');
 const bent = require('bent');
 const fs = require('fs');
 
@@ -42,6 +43,33 @@ const testGoogleStt = async(logger, credentials) => {
   }
 };
 
+const testDeepgramStt = async(logger, credentials) => {
+  const {api_key} = credentials;
+  const deepgram = new Deepgram(api_key);
+
+  const mimetype = 'audio/wav';
+  const source = {
+    buffer: fs.readFileSync(`${__dirname}/../../data/test_audio.wav`),
+    mimetype: mimetype
+  };
+
+  return new Promise((resolve, reject) => {
+    // Send the audio to Deepgram and get the response
+    deepgram.transcription
+      .preRecorded(source, {punctuate: true})
+      .then((response) => {
+        //logger.debug({response}, 'got transcript');
+        if (response?.results?.channels[0]?.alternatives?.length > 0) resolve(response);
+        else reject(new Error('no transcript returned'));
+        return;
+      })
+      .catch((err) => {
+        logger.info({err}, 'failed to get deepgram transcript');
+        reject(err);
+      });
+  });
+};
+
 const testAwsTts = (logger, credentials) => {
   const polly = new Polly(credentials);
   return new Promise((resolve, reject) => {
@@ -138,5 +166,6 @@ module.exports = {
   testMicrosoftStt,
   testWellSaidStt,
   testNuanceTts,
-  testNuanceStt
+  testNuanceStt,
+  testDeepgramStt
 };