The SoftSonic motor is a new, engineering breakthrough feature of Seagate's sound barrier technology (SBT). Using industry-standard tests, the Barracuda ATA IV one-disc model emits only 2.0 bels while spinning and 2.4 bels while seeking; the human ear can't hear sounds below 2.5 bels. Seagate's SBT also reduces noise using specialized seek algorithms, SeaShield. top cover and internal dampers, resonance reduction, spin commutation and other mechanical and materials design optimizations.