"Hear Yourself Think"

"Hear Yourself Think" is the slogan behind the Noren Products Acoustilock series of PC enclosures.
Available in single PC configurations up to 14-space rack units, these products use a unique approach of acoustic insulation to reduce noise and heat pipes to dissipate heat. They claim up to an amazing 38dB(A) of noise reduction for their flagship model. No prices are listed on their web site, but chances are, these units are pricey.