JavaScriptAudioNode is an EventTarget.

client/dom/generated/monkey_dom.js

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // DO NOT EDIT
 // Auto-generated Dart DOM implementation.
 
 function DOM$EnsureDartNull(value) {
   return value === null ? (void 0) : value;
 }
@@ skipping 3703 matching lines @@
     c.prototype.ASSIGN_INDEX$operator = function(k, v) { this[k] = v; };
   }
   DOM$fixMembers(c, ['subarray']);
   c.$implements$Int8Array$Dart = 1;
   c.$implements$ArrayBufferView$Dart = 1;
 }
 function DOM$fixClass$JavaScriptAudioNode(c) {
   if (c.prototype) {
     c.prototype.bufferSize$getter = function() { return DOM$EnsureDartNull(this.bufferSize); };
   }
+  DOM$fixMembers(c, [
+    'addEventListener',
+    'dispatchEvent',
+    'removeEventListener']);
   c.$implements$JavaScriptAudioNode$Dart = 1;
   c.$implements$AudioNode$Dart = 1;
+  c.$implements$EventTarget$Dart = 1;
 }
 function DOM$fixClass$JavaScriptCallFrame(c) {
   if (c.prototype) {
     c.prototype.caller$getter = function() { return DOM$EnsureDartNull(this.caller); };
     c.prototype.column$getter = function() { return DOM$EnsureDartNull(this.column); };
     c.prototype.functionName$getter = function() { return DOM$EnsureDartNull(this.functionName); };
     c.prototype.line$getter = function() { return DOM$EnsureDartNull(this.line); };
     c.prototype.scopeChain$getter = function() { return DOM$EnsureDartNull(this.scopeChain); };
     c.prototype.sourceID$getter = function() { return DOM$EnsureDartNull(this.sourceID); };
     c.prototype.type$getter = function() { return DOM$EnsureDartNull(this.type); };
@@ skipping 6620 matching lines @@
 function native__NativeDomGlobalProperties_getWindow() {
   // TODO: Should the window be obtained from an isolate?
   return window;
 }
 
 // Declared in src/GlobalProperties.dart
 function native__NativeDomGlobalProperties_getDocument() {
   // TODO: Should the window be obtained from an isolate?
   return window.document;
 }