The audio quality of an MP3 file is determined by the sampling rate, which for CD-quality audio is 48 kHz. Testing an audio file may require you to use a variety of sampling rates, which may include 8 kHz, or 8 bit. This will result in a mono, or one-channel audio file. Converting MP3 files to 8 bit will require using a software program with an option for 8 kHz, such as the Easy Hi-Q Converter.
Go to the download webpage for the Easy Hi-Q Converter 1.7 (see Resources). Click the "Download Free Trial" button and save the file to your desktop. Double-click the "easyhiqconv.exe" file to install the program.
Double-click the "Easy Hi-Q Converter" icon to run the program.
Navigate to the location of the MP3 file that you want to convert from the left panel. Click the "+" that is next to "My Computer" to see all available drive letters. Any MP3 files that are in the selected folder will be displayed on the right panel.
Highlight the MP3 file or files that you want to convert. Click the "Add Selected" button at the top of the panel. This will display the Options window.
Put a check in the box for "MP3." Click the second drop-down selection box and select the option for "8 Kbps." Click the third drop-down box and select the option for "Mono."
Put a check in the radio button for "Same as Input Locations."
Click the "OK" button to close the Options window. Click the "Convert" button to begin the process.
If you want to save the converted files to a different location, click the radio button for "Specify Location."
The full version of the program will cost £16.20, as of December 2010.