diff --git a/js/photon-absorption/view/EmissionRateControlSliderNode.js b/js/photon-absorption/view/EmissionRateControlSliderNode.js
index 4ed298d..62a3a21 100644
--- a/js/photon-absorption/view/EmissionRateControlSliderNode.js
+++ b/js/photon-absorption/view/EmissionRateControlSliderNode.js
@@ -26,7 +26,8 @@ define( function( require ) {
   var Range = require( 'DOT/Range' );
   var Rectangle = require( 'SCENERY/nodes/Rectangle' );
   var Shape = require( 'KITE/Shape' );
-  // var StringUtils = require( 'PHETCOMMON/util/StringUtils' );
+  var StringUtils = require( 'PHETCOMMON/util/StringUtils' );
+  var utteranceQueue = require( 'SCENERY_PHET/accessibility/utteranceQueue' );
   var WavelengthConstants = require( 'MOLECULES_AND_LIGHT/photon-absorption/model/WavelengthConstants' );
 
   // constants
@@ -86,16 +87,65 @@ define( function( require ) {
     var parentBounds = sliderThumb.localToParentBounds( sliderBounds );
     this.emissionRateControlSlider.focusHighlight = new FocusHighlightPath( Shape.bounds( parentBounds ) );
 
-    // a11y
+    // a11y// takes a given frequency and returns the proper string for its associated rate
+    function mapFrequencyToString( freq ) {
+      // debugger;
+      // can be moved to constants file
+      var sliderRangeMap = [
+        {
+          range: {
+            contains: function ( val ) {
+              return val > 0 && val < 0.3;
+            }
+          },
+          text: 'slow'
+        },
+        {
+          range: {
+            contains: function( val ) {
+              return val >= 0.3 && val < 0.7;
+            }
+          },
+          text: 'moderate'
+        },
+        {
+          range: {
+            contains: function( val ) {
+              return val >= 0.7 && val <= 1;
+            }
+          },
+          text: 'fast'
+        }
+      ];
+
+      for ( var i = sliderRangeMap.length - 1; i >= 0; i-- ) {
+        if ( sliderRangeMap[ i ].range.contains ( freq ) ) {
+          return sliderRangeMap[ i ].text;
+        }
+      }
+    }
     this.emissionRateControlSlider.addAccessibleInputListener( {
       focus: function() {
         sliderThumb.backgroundRectangle.visible = true;
       },
       blur: function() {
         sliderThumb.backgroundRectangle.visible = false;
+      },
+      keyup: function() {
+        var frequencyText = mapFrequencyToString( model.emissionFrequencyProperty.get() );
+        var wavelengthText = WavelengthConstants.getLightSourceName( model.photonWavelengthProperty.get() );
+
+        utteranceQueue.addToBack( StringUtils.fillIn(
+          '{{wavelengthText}} photon rate, {{frequencyText}}',
+          { wavelengthText: wavelengthText, frequencyText: frequencyText }
+        ) );
       }
     } );
 
+    // a11y alerts for the slider
+    // model.emissionFrequencyProperty.lazyLink( function( frequency ) {
+    // } );
+
     // width of the background rectangle is larger than the slider to accentuate the thumb.
     var backgroundOffset = 4;
     this.backgroundRect = new Rectangle(
diff --git a/js/photon-absorption/view/MoleculeNode.js b/js/photon-absorption/view/MoleculeNode.js
index 5204859..e976ef0 100644
--- a/js/photon-absorption/view/MoleculeNode.js
+++ b/js/photon-absorption/view/MoleculeNode.js
@@ -17,7 +17,6 @@ define( function( require ) {
   var MoleculesAndLightA11yStrings = require( 'MOLECULES_AND_LIGHT/common/MoleculesAndLightA11yStrings' );
   var Node = require( 'SCENERY/nodes/Node' );
   var StringUtils = require( 'PHETCOMMON/util/StringUtils' );
-  // var Utterance = require( 'SCENERY_PHET/accessibility/Utterance' );
   var utteranceQueue = require( 'SCENERY_PHET/accessibility/utteranceQueue' );
   var NO = require( 'MOLECULES_AND_LIGHT/photon-absorption/model/molecules/NO' );
   var CO = require( 'MOLECULES_AND_LIGHT/photon-absorption/model/molecules/CO' );