*/
int sound_manager_stop_virtual_stream(virtual_sound_stream_h virtual_stream);
+/**
+ * @internal
+ * @brief Sets the virtual stream volume.
+ * @since_tizen 5.5
+ * @param[in] virtual_stream The handle of virtual stream
+ * @param[in] ratio The volume ratio to be set (Min.:0.0 ~ Max.:1.0, default:1.0)
+ * @return @c 0 on success,
+ * otherwise a negative error value
+ * @retval #SOUND_MANAGER_ERROR_NONE Success
+ * @retval #SOUND_MANAGER_ERROR_INVALID_PARAMETER Invalid parameter
+ * @retval #SOUND_MANAGER_ERROR_INVALID_STATE Invalid state
+ * @retval #SOUND_MANAGER_ERROR_INTERNAL Internal error inside the sound system
+ * @see sound_manager_create_virtual_stream()
+ * @see sound_manager_destroy_virtual_stream()
+ * @see sound_manager_start_virtual_stream()
+ */
+int sound_manager_set_virtual_stream_volume(virtual_sound_stream_h virtual_stream, double ratio);
+
/**
* @internal
* @brief Set sound filter and apply to audio streams given selected stream type.