When a digital audio application and the sound card interact to exchange data for processing or reproduction, the signal typically travels through several layers of mediating software from the operating system. This, among other factors along the signal chain, is what causes latency and poor audio quality. The ASIO or Audio Stream Input/Output protocol for audio drivers is one of the solutions that address this problem by enabling audio applications and devices to bypass the operating system and communicate through a more direct route.
Not all sound cards come in a PCI card-type form factor or are on-board chips. Some, usually the professional-grade models, are completely external devices that connect to the PC through high-speed ports such as USB or Firewire. The USB Audio ASIO driver is underlying software that can support this type of configuration. This particular audio driver provides the ASIO advantage for systems that use ASIO-aware applications (Cubase, Reason, Native Instruments, etc.) in tandem with external USB sound cards.
This update for the USB Audio ASIO driver is version 2.8.45 released August 30, 2010. Among the audio performance-enhancing improvements introduced in this version are: broader sampling rate support (32, 44.1, 48 KHz), wider sampling resolution (from 16 to 24-bit), and support for ASIO 2. Compatible platforms for this update are Windows 2003, XP, Vista, Windows 7, and Windows Server 2008.
A free trial version of USB Audio ASIO driver is available here for download. Take note that this trial version will produce a short beep every 30 seconds of audio.