Long press menu (shift+f6) to toggle spoken feedback.

ash/ash.gyp

Index: ash/ash.gyp
diff --git a/ash/ash.gyp b/ash/ash.gyp
index f31dc065454f08dbcb4b734c7e81e6f68aa6835b..a78d666e6216ffa53f3bb2b2449c0a789cb561e9 100644
--- a/ash/ash.gyp
+++ b/ash/ash.gyp
@@ -64,10 +64,16 @@
         'accelerators/debug_commands.h',
         'accelerators/exit_warning_handler.cc',
         'accelerators/exit_warning_handler.h',
+        'accelerators/key_hold_detector.cc',
+        'accelerators/key_hold_detector.h',
         'accelerators/focus_manager_factory.cc',
         'accelerators/focus_manager_factory.h',
+        'accelerators/magnifier_key_scroller.cc',
+        'accelerators/magnifier_key_scroller.h',
         'accelerators/nested_dispatcher_controller.cc',
         'accelerators/nested_dispatcher_controller.h',
+        'accelerators/spoken_feedback_toggler.cc',
+        'accelerators/spoken_feedback_toggler.h',
         'accessibility_delegate.h',
         'audio/sounds.cc',
         'audio/sounds.h',
@@ -177,8 +183,6 @@
         'magnifier/magnification_controller.cc',
         'magnifier/magnification_controller.h',
         'magnifier/magnifier_constants.h',
-        'magnifier/magnifier_key_scroller.cc',
-        'magnifier/magnifier_key_scroller.h',
         'magnifier/partial_magnification_controller.cc',
         'magnifier/partial_magnification_controller.h',
         'metrics/user_metrics_recorder.cc',
@@ -641,12 +645,16 @@
         }],
         ['use_x11!=1', {
           'sources/': [
+            ['exclude', 'accelerators/key_hold_detector.cc'],
+            ['exclude', 'accelerators/key_hold_detector.h'],
+            ['exclude', 'accelerators/magnifier_key_scroller.cc'],
+            ['exclude', 'accelerators/magnifier_key_scroller.h'],
+            ['exclude', 'accelerators/spoken_feedback_toggler.cc'],
+            ['exclude', 'accelerators/spoken_feedback_toggler.h'],
             ['exclude', 'display/display_change_observer_chromeos.cc'],
             ['exclude', 'display/display_change_observer_chromeos.h'],
             ['exclude', 'display/display_error_observer_chromeos.cc'],
             ['exclude', 'display/display_error_observer_chromeos.h'],
-            ['exclude', 'magnifier/magnifier_key_scroller.cc'],
-            ['exclude', 'magnifier/magnifier_key_scroller.h'],
           ],
         }],
         ['chromeos==1', {
@@ -828,7 +836,9 @@
         'accelerators/accelerator_controller_unittest.cc',
         'accelerators/accelerator_filter_unittest.cc',
         'accelerators/accelerator_table_unittest.cc',
+        'accelerators/magnifier_key_scroller_unittest.cc',
         'accelerators/nested_dispatcher_controller_unittest.cc',
+        'accelerators/spoken_feedback_toggler_unittest.cc',
         'autoclick/autoclick_unittest.cc',
         'desktop_background/desktop_background_controller_unittest.cc',
         'desktop_background/wallpaper_resizer_unittest.cc',
@@ -855,7 +865,6 @@
         'keyboard_overlay/keyboard_overlay_delegate_unittest.cc',
         'keyboard_overlay/keyboard_overlay_view_unittest.cc',
         'magnifier/magnification_controller_unittest.cc',
-        'magnifier/magnifier_key_scroller_unittest.cc',
         'root_window_controller_unittest.cc',
         'screen_util_unittest.cc',
         'screensaver/screensaver_view_unittest.cc',
@@ -984,9 +993,10 @@
         }],
         ['use_x11!=1', {
           'sources/': [
+            ['exclude', 'accelerators/magnifier_key_scroller_unittest.cc'],
+            ['exclude', 'accelerators/spoken_feedback_toggler_unittest.cc'],
             ['exclude', 'display/display_change_observer_chromeos_unittest.cc'],
             ['exclude', 'display/display_error_observer_chromeos_unittest.cc'],
-            ['exclude', 'magnifier/magnifier_key_scroller_unittest.cc'],
           ],
         }],
         ['chromeos==1', {