Variations in fan speed are normal. Fans might be getting louder due to losing grease, or having dust accumulate in it. However, fan speeds are usually tied to the temperature of your CPU and GPU.
If you want an exact temperature of your CPU and GPU, try HWmonitor: http://www.cpuid.com/softwares/hwmonitor.html
Hwmonitor is a non-evasive way of determining the actual temperature of your laptop. Your CPU should be idling anywhere from 40s-50s [Celsius]. GPU should idle in the same range; 40s-50s.
Good luck
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QOSMIO - x505 q8102X
i7-2630QM , GTX 460m , 18.4" screen @ 1680x945p