I have written up a procedure for you to try:
- Restore your phone.
- Test - if successful go to last.
- Take your iPhone to the nearest Apple store and tell them what's happening.
- Test the issue with the refurbished iPhone they gave you to replace the one that was malfunctioning - if successful go to last.
- Enjoy your "15 more minutes" feeling.
Failing all of these, your alarm is going off and you're sleeping through it because you stayed up too late playing WoW, drinking, coding, whatever. It eventually stops making noise and leaves the message on the screen. Try placing the phone across the room so you have to get up to turn it off. See if that helps. Either way, now you have a newly refurbished iPhone 4.
Please forgive the snarky nature of this answer. I wrote it after my alarm didn't go off in the morning due to a push notification.
The Alarm sound is independent from the hardware mute switch. Essentially there are 2 volume states for iOS. One is for system notifications (Alarms, calendar events, emails, SMS, other notifications etc) and one is for playback of music etc in Games, playing music, videos etc etc.
Apps have a choice what to do what the hardware switch is set to mute. The intention is that even with the switch set, you can still hear sounds, the thinking being you have specifically chosen to hear those sounds at that moment in time by playing the video (for example). Therefore, many such sounds "play through" the hardware mute. However, some apps decide to take things another way, and look for the switch state, and match the App actions accordingly.
Both of these volume levels can be set to different levels. In fact, there are sub-levels of the App volume level, in that you can retain different levels depending on whether you are using the speaker, headphones, or a headset (It will switch to the last set level for each type as and when you plug/unplug the relevant accessory)
Either way, the Alarm will ring using the normal notifications volume level (the one you can set at the home screen without any apps running, labeled "Ringer") regardless of your mute switch setting, so just turn it up, flip the mute switch, and unless you fire up a game whilst sleep-gaming, the only sound that will ever disturb you is the Alarm, and/or someone using Find my Phone, which also plays (actually at Max volume) regardless of the setting.
Best Answer
Yes and no. The iPhone has a reasonably sophisticated, system-level, sound setup with the goal of making it easy for the user. It has several volume options divided up. (1) all alerts such as ringtones and Alarm.app alarms, (2) Siri, (3) content playback such as music or video.
Yes: What you can do to directly fix your problem is to use the vibrate/silence switch on the side of the phone instead of turning the ringer volume down. In the on position (orange is showing, a vibration is felt when the switch is initially turned on), phone calls, texts, and such will vibrate, but the alarm will still play at whatever the ringer volume was set to before turning the vibrate switch on.
One other thing you could do is leave the volume switch on and purchase, or create, a silent ringer - no music in it. Then you can select that ringer as your default ringer and calls will be "silenced". This method is generally not preferred because custom contact ringers will override this ringer.
No: The vibrate switch is actually the only way to separate the ringer volume from the alarm volume. If the vibrate switch is off (calls are heard), then the alarm volume will match the ringer volume.