diff --git a/Tone/core/Types.js b/Tone/core/Types.js
index 559a8f7b..ff09567d 100644
--- a/Tone/core/Types.js
+++ b/Tone/core/Types.js
@@ -115,6 +115,11 @@ define(["Tone/core/Tone"], function (Tone) {
 		 *  @typedef {Note}
 		 */
 		Note : "note",
+		/** 
+		 *  One millisecond is a thousandth of a second. 
+		 *  @typedef {Milliseconds}
+		 */
+		Milliseconds : "milliseconds",
 		/** 
 		 *  A string representing a duration relative to a measure. 
 		 *  <ul>
diff --git a/Tone/effect/Chorus.js b/Tone/effect/Chorus.js
index 8d026482..f57118ed 100644
--- a/Tone/effect/Chorus.js
+++ b/Tone/effect/Chorus.js
@@ -12,7 +12,7 @@ function(Tone){
 	 *	@constructor
 	 *	@extends {Tone.StereoXFeedbackEffect}
 	 *	@param {Frequency|Object} [frequency] The frequency of the LFO.
-	 *	@param {Number} [delayTime] The delay of the chorus effect in ms. 
+	 *	@param {Milliseconds} [delayTime] The delay of the chorus effect in ms. 
 	 *	@param {NormalRange} [depth] The depth of the chorus.
 	 *	@example
 	 * var chorus = new Tone.Chorus(4, 2.5, 0.5);
@@ -143,7 +143,7 @@ function(Tone){
 	 * will give a more pronounced effect. Nominal range a delayTime
 	 * is between 2 and 20ms. 
 	 * @memberOf Tone.Chorus#
-	 * @type {Number}
+	 * @type {Milliseconds}
 	 * @name delayTime
 	 */
 	Object.defineProperty(Tone.Chorus.prototype, "delayTime", {