At this point I can't remember what my computer sounded like when I ran Windows, but regardless there is a constant hard drive noise that is bothering me- I'm running Ubuntu 14.04. It is a whirring sound, so I would like to think it's the fan, but running sensors, even when it reports 0rpm for the fan, I hear this noise. While it isn't incredibly loud, it is noticeable, especially when the computer isn't making any other noise, e.g. music. How could I check to see if it is indeed the hard drive making the noise, and how could I fix the problem? 
Ouput of sensors follows: 
acpitz-virtual-0
Adapter: Virtual device
temp1:        +51.0°C  (crit = +200.0°C)
thinkpad-isa-0000
Adapter: ISA adapter
fan1:           0 RPM
coretemp-isa-0000
Adapter: ISA adapter
Physical id 0:  +51.0°C  (high = +84.0°C, crit = +100.0°C)
Core 0:         +49.0°C  (high = +84.0°C, crit = +100.0°C)
Core 1:         +51.0°C  (high = +84.0°C, crit = +100.0°C)
nouveau-pci-0200
Adapter: PCI adapter
temp1:            N/A  (high = +95.0°C, hyst =  +3.0°C)
                       (crit = +105.0°C, hyst =  +5.0°C)
                       (emerg = +135.0°C, hyst =  +5.0°C)
