Index: src/js/media/models/attachments.js
===================================================================
--- src/js/media/models/attachments.js	(revision 45546)
+++ src/js/media/models/attachments.js	(working copy)
@@ -293,6 +293,8 @@
 		this.reset( [], { silent: true } );
 		this.observe( attachments );
 
+		// For the search results.
+		this.trigger( 'attachments:mirror:done', this );
 		return this;
 	},
 	/**
@@ -332,6 +334,9 @@
 			if ( this === attachments.mirroring ) {
 				deferred.resolveWith( this );
 			}
+
+			// For the search results.
+			attachments.trigger( 'attachments:more:done', this );
 		});
 
 		return deferred.promise();
Index: src/js/media/models/query.js
===================================================================
--- src/js/media/models/query.js	(revision 45546)
+++ src/js/media/models/query.js	(working copy)
@@ -287,6 +287,7 @@
 				query = _.find( queries, function( query ) {
 					return _.isEqual( query.args, args );
 				});
+				// window.console.log( 'models query search cached', query );
 			} else {
 				queries = [];
 			}
@@ -298,6 +299,7 @@
 					args:  args
 				} ) );
 				queries.push( query );
+				// window.console.log( 'models query search request', query );
 			}
 
 			return query;
Index: src/js/media/views/attachments/browser.js
===================================================================
--- src/js/media/views/attachments/browser.js	(revision 45546)
+++ src/js/media/views/attachments/browser.js	(working copy)
@@ -83,8 +83,30 @@
 		}
 
 		this.collection.on( 'add remove reset', this.updateContent, this );
+
+		// Non-cached attachments query.
+		this.collection.on( 'attachments:more:done', this.queryDone, this );
+		// Cached attachments query.
+		this.collection.on( 'attachments:mirror:done', this.queryDone, this );
 	},
 
+	queryDone: function() {
+		var count;
+
+		if ( this.collection.mirroring.args.s ) {
+			count = this.collection.length;
+			window.console.log( 'browser queryDone', this.collection );
+			window.console.log( 'search results: ' + count );
+
+			if ( 0 === count ) {
+				wp.a11y.speak( l10n.noMediaTryNewSearch );
+				return;
+			}
+
+			wp.a11y.speak( l10n.mediaFound.replace( '%d', count ) );
+		}
+	},
+
 	editSelection: function( modal ) {
 		// When editing a selection, move focus to the "Return to library" button.
 		modal.$( '.media-button-backToLibrary' ).focus();
Index: src/js/media/views/search.js
===================================================================
--- src/js/media/views/search.js	(revision 45546)
+++ src/js/media/views/search.js	(working copy)
@@ -22,8 +22,7 @@
 	},
 
 	events: {
-		'input':  'search',
-		'keyup':  'search'
+		'input': 'search'
 	},
 
 	/**
@@ -40,7 +39,7 @@
 		} else {
 			this.model.unset('search');
 		}
-	}, 300 )
+	}, 500 )
 });
 
 module.exports = Search;
Index: src/wp-includes/media.php
===================================================================
--- src/wp-includes/media.php	(revision 45546)
+++ src/wp-includes/media.php	(working copy)
@@ -3812,7 +3812,9 @@
 		'filterByType'                => __( 'Filter by type' ),
 		'searchMediaLabel'            => __( 'Search Media' ),
 		'searchMediaPlaceholder'      => __( 'Search media items...' ), // placeholder (no ellipsis)
-		'noMedia'                     => __( 'No media files found.' ),
+		'noMedia'                     => __( 'No media items found.' ),
+		'mediaFound'                  => __( 'Number of media items found: %d' ),
+		'noMediaTryNewSearch'         => __( 'No media items found. Try a different search.' ),
 
 		// Library Details
 		'attachmentDetails'           => __( 'Attachment Details' ),
Index: src/wp-includes/script-loader.php
===================================================================
--- src/wp-includes/script-loader.php	(revision 45546)
+++ src/wp-includes/script-loader.php	(working copy)
@@ -1507,7 +1507,7 @@
 
 	// To enqueue media-views or media-editor, call wp_enqueue_media().
 	// Both rely on numerous settings, styles, and templates to operate correctly.
-	$scripts->add( 'media-views', "/wp-includes/js/media-views$suffix.js", array( 'utils', 'media-models', 'wp-plupload', 'jquery-ui-sortable', 'wp-mediaelement', 'wp-api-request' ), false, 1 );
+	$scripts->add( 'media-views', "/wp-includes/js/media-views$suffix.js", array( 'utils', 'media-models', 'wp-plupload', 'jquery-ui-sortable', 'wp-mediaelement', 'wp-api-request', 'wp-a11y' ), false, 1 );
 	$scripts->add( 'media-editor', "/wp-includes/js/media-editor$suffix.js", array( 'shortcode', 'media-views' ), false, 1 );
 	$scripts->add( 'media-audiovideo', "/wp-includes/js/media-audiovideo$suffix.js", array( 'media-editor' ), false, 1 );
 	$scripts->add( 'mce-view', "/wp-includes/js/mce-view$suffix.js", array( 'shortcode', 'jquery', 'media-views', 'media-audiovideo' ), false, 1 );