Integrating Technology in the Second Language Classroom

Edit this poorly recorded sound using Audacity to clean up the following problems:
 

• Select the entire sound and Center wave (DC Bias adjust) [Effect/Normalize/Remove DC offset] [Transform/Amplitude/Amplify]
• Remove noise (You are likely to need to review this procedure before doing it)  [Effect/Noise removal] [Transform/Noise Reduction]
• Find and remove extra words, hesitation, noises   [Edit / Cut or Trim]
• Find and silence noises that should not be cut (i.e. Without damaging the rhythm) [Effect/Amplify] [Transform/Amplitude/Amplify]
• Normalize close to maximum levels   [Effect/Normalize] [Transform/Amplitude/Normalize]
• Save as mp3 : 56 Kbps, 22050 Hz, mono [Export as/mp3] [Save as/mp3]


Refer to the previous instructions on sound editing if needed.

To produce small sound file, be sure to limit the sample rate (11 kHz may be adequate for voice) and use mono reather than stereo.  A 44 kHz stereo WAV file will be 8 times as large as an 11 kHz mono WAV file.

MP3 compression will also make a significant difference but may require some setup adjustments to control how much compression you want to use. There is always a trade off between file size and sound quality. You just have to try out some different mp3 settings and decide what sounds ok to your ear. The main compression setting for mp3 is Kbps (kilobits per second = a measure of how many 1s and 0s in the file are used to represent one second of sound). Typical mp3 music files are stereo, 44 kHz, 128 kbps. This is much better quality than you need for voice.