Audio Devices (Microphone, Sound Card, Special Software)

by Jasmine Denise Calalang Santos

Microphone

1. What is it? What is it for?

A microphone is an audio-input device that translates acoustical energy (sound waves) into electric energy (audio signal) that the computer can read and process. Essentially, the microphone has one use: TO TRANSFER SOUND. Now, this sound that is transferred can either be recorded, amplified, or literally transferred to a receiver in another location. It is most commonly used in computers, recording studios, radio, concerts, telephones, and PA systems.

2. What does it look like?

3. What is the technology behind it?

“Microphones are a type of transducer - a device which converts energy from one form to another.” What all microphones have in common is the diaphragm, which is the first part of the microphone that is affected by the sound waves. Once it vibrates, all other parts of the microphone also vibrate. These simultaneous vibrations create a collective vibration which is then converted to an electric current that becomes the audio signal that is then sent to a sound card to be processed.

Sound Card

1. What is it? What is it for?

A sound card is a kind of expansion card that facilitates the input and output of sounds to and from a computer. It sends audio information to a particular output or compatible audio device. Some of the most common uses of a sound card are “to provide the audio components from the multimedia applications like music, video, presentation, games, etc.

2. What does it look like?

Soundcards have a line of connectors that read the electric signals sent by the microphone or another audio input device and digitalizes these signals for the computer to understand. These digitalized signals are then stored in the computer’s hard disk for further processing to be done by special software.

Special Software

1. What is it? What is it for?

Special software for voice recognition, in general, is a software that interprets the digitalized signals from the sound card into text-style documents or into commands for the computer to fulfill. “Simply put, it substitutes voice entry for keyboard entry.”

2. What does it look like?

3. What is the technology behind it?

Sound waves, being waves, come in frequencies that vary from low to high. Each sound is supposed to have a corresponding frequency that is unique to it. What the special software has is a collection of these frequencies. It analyzes the sound waves of the input and matches it with its own library, by comparing their “voiceprints”. In a nutshell, "it’s pattern matching.”

References

http://www.mediacollege.com/audio/microphones/how-microphones-work.html (Accessed August 6, 2009)

http://www.tech-faq.com/microphone.shtml (Accessed August 6, 2009

http://blogs.menupages.com/southflorida/category/nightlife_bars/ (Accessed August 6, 2009

http://www.mediacollege.com/audio/microphones/how-microphones-work.html (Accessed August 6, 2009)

http://www.pc.speakers.ie/ (Accessed August 7, 2009)

http://ezinearticles.com/?How-Does-A-Sound-Card-Work&id=847430 (Accessed August 7, 2009)

http://www.winrag.com/season2issue1.htm (Accessed August 7, 2009)

http://www.foxdelta.com/products/sc1-old.htm (Accessed August 7, 2009)

http://electronics.howstuffworks.com/speech-recognition.htm (Accessed August 7, 2009)

http://www.wisegeek.com/what-is-speech-recognition-software.htm (Accessed August 7, 2009)

http://askbobrankin.com/voice_recognition.html (Accessed August 7, 2009)