We have been looking for a USB microphone for use with Dragon NaturallySpeaking 9 (Medical). The intended platform is a Fujitsu P1510D subnotebook.
Features of interest are a small, handheld, USB, vocal microphone with good speech audio quality, noise canceling and a "noiseless" audio on-off switch.
The closest microphone that we have found that meets at least some of these specifications is the Samson C01U. The audio quality is excellent and combined electrical and ambient noise is only slightly higher than that of our favorite combination of a Sennheiser MD431 II microphone, a Grace 101 pre-amplifier and a Delta 24/96 sound converter. The Hypercardioid pattern is very effective for reducing interference from ambient audio noise sources.
Windows 2003 Server and NaturallySpeaking correctly recognized and setup the USB microphone. There was no requirement for any add-on device drivers.
As has been our repeated experience with NaturallySpeaking 9, it is possible to dictate our sample medical report without any recognition errors.
The bad news is that the C01U is a large, heavy microphone and it lacks an audio switch. The microphone is 7" long and has a maximum diameter of about 2.25". It weighs two pounds. Frequency response is 20-18000Hz. Sensitivity is -33dB. It has a hypercardioid pattern which is highly desirable for combined vocal/noise canceling applications. Samson markets two other USB microphones. The C03U is another condenser microphone that differs from the C01U in that it has an adjustable polar pattern. The Q1U is a dynamic microphone. Its frequency response is 50-16000Hz. Sensitivity is -54dB. The polar pattern is Super Cardioid rather than Hypercardioid. It is physically a smaller microphone and weighs 13 ounces.
Generally speaking, professional quality condenser microphones have a wider frequency spectrum, higher audio output levels and better sound quality compared with their dynamic counterparts. The wider frequency spectrum is, however, probably a disadvantage for speech recognition applications. The condenser technology tends to be mechanically fragile and, at least with the Samson models, the condenser version is much heavier than the dynamic.
As advertised, the C01U delivers studio quality audio for a remarkably reasonable price (about $75). It works well for speech recognition applications, but is a monster in terms of its size and weight.