In a similar move to Supermicro's offer of quiet small office servers, IBM announced today new BladeCenter kits that were aimed at people in noise-sensitive areas.

Calling it the "Office Ready Kit", the kit is designed for BladeServer S series, which are their new systems geared for areas where both noise and power consumption are key. The latter of these has become a huge topic the past two years, and less noise is almost always good. The kitted servers have several modifications to them that help absorb noise, such as air filters and a "muffler" of sorts on the enclosure . They claim the servers are half as loud as a comparable HP unit:

"Listening tests have judged a 10 decibel difference to be twice as loud, which is significant," said Dr. Noral Stewart, President of Stewart Acoustical Consultants and a member of the National Council of Acoustical Consultants. "For this reason, IBM BladeCenter S is the better choice for any office or work environment that requires normal spoken communication."
Overall, they claim the conversion lowers system noise to 60 decibels, which is not bad at all for a server. You can read the full press release at IBM's site.