From 4855fec4f5b7a626cff4539df55433a4b0ae3128 Mon Sep 17 00:00:00 2001
From: akirilyuk <a.kirilyuk@cognigy.com>
Date: Tue, 15 Feb 2022 13:55:18 +0100
Subject: [PATCH] add vad

---
 lib/tasks/gather.js | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/lib/tasks/gather.js b/lib/tasks/gather.js
index f801e6da..a150056f 100644
--- a/lib/tasks/gather.js
+++ b/lib/tasks/gather.js
@@ -44,6 +44,10 @@ class TaskGather extends Task {
       this.profanityOption = recognizer.profanityOption || 'raw';
       this.requestSnr = recognizer.requestSnr || false;
       this.initialSpeechTimeoutMs = recognizer.initialSpeechTimeoutMs || 0;
+
+      /* vad: if provided, we dont connect to recognizer until voice activity is detected */
+      const {enable, voiceMs = 0, mode = -1} = recognizer.vad || {};
+      this.vad = {enable, voiceMs, mode};
     }
 
     this.digitBuffer = '';
@@ -197,7 +201,11 @@ class TaskGather extends Task {
 
   async _initSpeech(cs, ep) {
     const opts = {};
-
+    if (this.vad.enable) {
+      opts.START_RECOGNIZING_ON_VAD = 1;
+      if (this.vad.voiceMs) opts.RECOGNIZER_VAD_VOICE_MS = this.vad.voiceMs;
+      if (this.vad.mode >= 0 && this.vad.mode <= 3) opts.RECOGNIZER_VAD_MODE = this.vad.mode;
+    }
     if ('google' === this.vendor) {
       if (this.sttCredentials) opts.GOOGLE_APPLICATION_CREDENTIALS = JSON.stringify(this.sttCredentials.credentials);
       Object.assign(opts, {