The current default notification tone for calendar events on the Android phone is very feeble. Even at full volume, if you are not nearby you cannot hear the tone. To make a tone much louder or playing longer, do the following:
- On the SD Card create a folder called media.
- Within the media folder, create another folder called audio
- Within the audio folder, create one more called notifications
- Copy the audio file that you want to use as a notification into the sdcard/media/audio/notifications folder.
- Now you can use that audio file will show up in the notifications list when you add a new calendar event.