Welcome to Android Central! What do you mean when you say it whistles and nothing is there? Do you mean that you have the whistle tone set as the notification tone, and you hear that, but nothing is in the notification bar?
What do you mean by using loads of memory? Are you talking about the Internal Storage (in the
Settings>Storage menu)? Or RAM usage (in the
Settings>Apps>Running menu? Those are two different things.
When you make a voice recording, are you saying that when you play it back, all you hear are strange garbled noises? Or are they in the background?
For the battery, it would help to see some battery stats. Charge up to 100%, then let it drain to 20-30% with normal usage, without charging in between. Then show us:
1. The main
Settings>Battery screen.
2. The fullscreen battery graph screen (which shows Awake time and Cell Signal Strength).
3. The Screen category (to see total Screen On time).
4. The Cell Standby category, if present (to see Time Without Signal).
http://forums.androidcentral.com/am...ide-how-post-screenshots-android-central.html
You might have to install a 3rd party battery monitor, like GSam Battery Monitor, to get the Cell Signal Strength graph.