cpu - Fan speed high since upgrade to 12.04

Since I have updated to 12.04 LTS my desktop pc's fan runs permanently with high speed and is annoyingly noisy. CPU temperature is low.
Here is what the sensors command gets me:

nouveau-pci-0400
Adapter: PCI adapter
temp1:        +48.0°C  (high = +100.0°C, crit = +115.0°C)
coretemp-isa-0000
Adapter: ISA adapter
Core 0:       +39.0°C  (high = +82.0°C, crit = +100.0°C)
Core 1:       +40.0°C  (high = +82.0°C, crit = +100.0°C)
Core 2:       +37.0°C  (high = +82.0°C, crit = +100.0°C)
Core 3:       +44.0°C  (high = +82.0°C, crit = +100.0°C)
f8000-isa-0a00
Adapter: ISA adapter
+3.3V:        +3.34 V
3VSB:         +3.38 V
Vbat:         +3.23 V
fan1:        1675 RPM
fan2:         959 RPM
fan3:           0 RPM  ALARM
fan4:           0 RPM
temp1:        +42.0°C  (high = +70.0°C, hyst = +60.0°C)
temp2:        +25.0°C  (high = +100.0°C, hyst = +85.0°C)
temp3:        +24.0°C  (high = +100.0°C, hyst = +85.0°C)

Same issue of noisy fan has been noted in Dell 1555 after upgrade to 12.04 with output of sensors command as below:

acpitz-virtual-0
Adapter: Virtual device
temp1:        +51.0°C  (crit = +100.0°C)
temp2:        +59.0°C  (crit = +100.0°C)
temp3:        +79.0°C  (crit = +100.0°C)
radeon-pci-0100
Adapter: PCI adapter
temp1:        +80.0°C

Is there a way to figure out which application is causing it?