diff --git a/src/PHPVideoToolkit/AudioFormat.php b/src/PHPVideoToolkit/AudioFormat.php
index d80c91c..d284be3 100644
--- a/src/PHPVideoToolkit/AudioFormat.php
+++ b/src/PHPVideoToolkit/AudioFormat.php
@@ -396,7 +396,7 @@ public function setAudioQuality($quality)
             }
             else if (is_int($quality) === false && is_float($quality) === false)
             {
-                throw new \InvalidArgumentException('The volume value must be an integer or float value.');
+                throw new \InvalidArgumentException('Audio quality value must be an integer or float value.');
             }
             
 //          interpret quality into ffmpeg value