Volume adjust sound is played only if spoken feedback is enabled.

chrome/browser/ui/ash/volume_controller_chromeos.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/ash/volume_controller_chromeos.h"
 
 #include "ash/ash_switches.h"
 #include "ash/audio/sounds.h"
 #include "base/command_line.h"
 #include "chrome/browser/browser_process.h"
@@ skipping 12 matching lines @@
 // Percent by which the volume should be changed when a volume key is pressed.
 const double kStepPercentage = 4.0;
 
 bool VolumeAdjustSoundEnabled() {
   return !CommandLine::ForCurrentProcess()->HasSwitch(
       chromeos::switches::kDisableVolumeAdjustSound);
 }
 
 void PlayVolumeAdjustSound() {
   if (VolumeAdjustSoundEnabled())
-    ash::PlaySystemSoundAlways(chromeos::SOUND_VOLUME_ADJUST);
+    ash::PlaySystemSoundIfSpokenFeedback(chromeos::SOUND_VOLUME_ADJUST);
 }
 
 }  // namespace
 
 VolumeController::VolumeController() {
   CrasAudioHandler::Get()->AddAudioObserver(this);
   ui::ResourceBundle& bundle = ui::ResourceBundle::GetSharedInstance();
   if (VolumeAdjustSoundEnabled()) {
     media::SoundsManager::Get()->Initialize(
         chromeos::SOUND_VOLUME_ADJUST,
@@ skipping 57 matching lines @@
       audio_handler->GetOutputVolumePercent(),
       audio_handler->IsOutputMuted());
 }
 
 void VolumeController::OnOutputMuteChanged() {
   CrasAudioHandler* audio_handler = CrasAudioHandler::Get();
   extensions::DispatchVolumeChangedEvent(
       audio_handler->GetOutputVolumePercent(),
       audio_handler->IsOutputMuted());
 }