The two fans generate a bit of noise under power, and would probably be noticeable from outside of the case. The whine isn't particularly high pitched however. To listen to this heatsink for yourself in operation, be sure to click on the little headphones icon below and download the Acoustic Sample MP3 file.

(high) FrostyTech Acoustic Sampling Chamber
Standard Waveform view of a 10 second recording. Click on the headphones to listen to an MP3 recording of this heatsink in operation.

Sound Level Measurements:

Listening to the actual noise a heatsink makes allows you to hear what pure numbers alone cannot get across. To further emphasize FrostyTech's reliance on cold hard facts when evaluating a heatsink, we also take Decibel readings with a sound level meter. These results may be higher than the manufacturer's listed specs, but then again these are real world measurements. Measurements are made on the dB (A) scale.

FrostyTech Sound Level Results
-	Manufacturer	Model	Noise Level	Scale
	Verax	P16	35.3 dB	Quiet
	Spire	SP420B8	40.2 dB
	Verax (high)	P16Cu	40.1 dB
	Zalman	CNPS7000-Cu	41.7 dB
	ArcticCooling	SuperSilent4 Pro	41.8 dB
	Zalman	CNPS6500-AlCu	47.4/28.9 dB
	Intel	Socket 478	42.5 dB
	CoolJag	JVC661A	43.9 dB
	Arkua	8456X-8T	46.5 dB
	Evercool	NW9F715CA	47.3 dB
	Intel	Stock 3.06GHz	47.5 dB
	Arkua	Q85X-7J	49.0 dB
	Arkua	848X-6B	49.3 dB
	Taisol	CEP426151A	50.7 dB
	Scythe	Kamakaze	51.0 dB
	Arkua	838T-7G	51.7 dB
	nPowertek	NPH-1	52.3 dB
	JMC	401100	53.0 dB
	Dynatron	DC1207BMW	53.0 dB
	Spire	SP411C5	53.2 dB
	Dynatron	DC1207BMY	53.2 dB
	Dynatron	DC1207BMX	53.4 dB
	Thermal Integration (high)	TI-V7035TN	53.6 dB
	Zalman	CNPS5700D-Cu	53.8 dB
	Globalwin	VA476	54.2 dB
	AVC	117140	56.1 dB
	Taisol	CEP447181	56.8 dB
	Taisol	CCP445172	57.5 dB
	Dynatron	DC1U-B02	62.2 dB
	Coolermaster	IHC-H71	64.4 dB
	Thermalright (high)	SLK-900U	67.2 dB	louder

The noise levels of the NPH-1 under power were measured to 52.3 dB. There are plenty of quieter heatsinks out there, but the pitch and whine of the fans isn't all that distracting. Plus as we're about to see, it is possible to run the nPowertek's fans at a lower RPM for near silent operation...