diff --git a/sound/mixer.h b/sound/mixer.h
index 28988256b31..dbb947cc7e7 100644
--- a/sound/mixer.h
+++ b/sound/mixer.h
@@ -142,7 +142,7 @@ public:
 	 * Start playing the given audio input stream.
 	 *
 	 * Note that the sound id assigned below is unique. At most one stream
-	 * with a given idea can play at any given time. Trying to play a sound
+	 * with a given id can play at any given time. Trying to play a sound
 	 * with an id that is already in use causes the new sound to be not played.
 	 *
 	 * @param type	the type (voice/sfx/music) of the stream