Microphone Selection Guide: Overview
Some Basics on Microphones
Virtually all of the commonly used microphones employed with personal computers are termed electret microphones and operate by using a permanently electrically charged material which alters its voltage when deflected by sound waves. Generally such microphones include a very small "pre-amplifier" to boost this signal and which requires application of a small external voltage. The alteration of voltage caused by sound waves (an analog type signal) travels into your PC sound card or external sound card and is converted into a digital signal which is interpreted by your PC software. There are, in addition, a variety of microphone types based on the outward design of the microphone:
- Wired headset microphones
- Wireless microphones
- Handheld microphones
- Table-mounted microphones
USB versus Non-USB Microphones
The issue of USB vs. Non-USB is an important topic. All microphones create an analog signal which needs to be converted to a digital signal for use with your computer software. The analog to digital conversion can happen outside of your computer (with either a converting device integrated into the microphone or with an independent converting device) or with your computer's on-board sound card. There are three main advantages to using a system doing the conversion outside of your computer:
- The external USB Sound Adapter accomplishes the process outside of the "electrically loud" environment of your personal computer and theoretically this may improve the quality of the process.
- External sound adapters are specifically designed for use with pc microphones are more apt to provide the correct voltage for your microphone and provide more predictably good results
- The use of an external sound adapter makes it more practical to move a voice profile from one computer to another and get predictably similar results, because both the user files and sound converting device are being moved.
The bottom line is that use of an external sound conversion device (adapter) is not essential but is highly recommended. Several microphones include built in USB devices, including the VXI Talk Pro USB 100 & 200, the Andrea NC 181 an 185 VM USB mics, the Speechware 6-in-1 microphone, the Samson Q1U, the Dictaphone PowerMic II, the Philips SpeechMic, and several of the wireless microphones such as the Sennheiser DW Office and Jabra 9470. If you purchase a standard analog microphone without an integrated USB sound adapter, we recommend purchasing an external USB sound adapter and interfacing your microphone to your computer with this adapter. You can read more about these devices near the bottom of this guide.