diff --git a/lib/helper.js b/lib/helper.js
index 86fefde..56d8287 100644
--- a/lib/helper.js
+++ b/lib/helper.js
@@ -147,7 +147,8 @@ function decryptAudioData(data,audioAesKey,audioAesIv) {
   const encrypted_length = block_count * BLOCK_SIZE;
   const remainder = data.length - encrypted_length;
 
-  const decipher = crypto.createDecipheriv('aes-128-cbc',audioAesKey,audioAesIv);
+  var audioAesKeyBuffer = new Buffer(audioAesKey, 'binary');
+  const decipher = crypto.createDecipheriv('aes-128-cbc', audioAesKeyBuffer, audioAesIv);
   decipher.setAutoPadding(false);
 
   const encrypted_data = data.slice(0,encrypted_length);
@@ -162,4 +163,3 @@ function decryptAudioData(data,audioAesKey,audioAesIv) {
 
   return output;
 };
-