While most PCs have a sound card, many sound cards lack sufficient quality and noise rejection on the microphone input to be a quality speech recognition sound card. Noise, low fidelity, and other artifacts are introduced to the microphone sound with these low-quality sound cards. As a result, the speech recognition software yields a lower level of accuracy as it struggles to differentiate between speech and noise.
Beyond noise issues, many good quality microphones (noteably the KnowBrainer Hands-Free Headset, the Sennheiser KnowBrainer, and ANC microphones) use electret condensers that require an active power source. Some PC sound cards (e.g. older IBM thinkpads) lack the proper supply voltage on the microphone channel to power these types of microphones.
The USB-based sounds cards we offer provide the quality signal processing, low noise, convenience, and reliable electret power source for your speech recognition needs.
USB sound card? Retrofit sound card? Speech recognition sound card? It doesn't matter the usage, these sounds cards are specifically designed to serve as quality sound cards that meet your needs for accuracy and portability (if needed).