Nero WaveEditor allows you to convert the sample format.  
You reach the Convert Sample Format Settings window via the Edit > Convert Sample Format entry in the menu bar.
The following drop-down menus are available in the Sample Format area:  
Sample rate
Provides different sample rates for selection. The default rate is 44100 Hz (CD).
Bit depth
Provides different bit depths for selection. The default setting is 16-bit (CD and DAT).
The following setting options are available in the Channels area:
Option buttons
Channels
Provides different output types for selection. With the selection of Surround 5.1 and 7.1 you have the option of creating a surround audio file with five or seven channels.
Drop-down menu
Down conversion method
Converts a surround audio file into a normal stereo audio file, a stereo audio file with artificial surround sound for headphones or a stereo audio file with artificial surround sound for speakers.
Only available with surround audio files.
The following drop-down menu is available in the Conversion settings area: 
Anti aliasing filters
This provides different kinds of anti-aliasing filters.
 
Sample Rate
The sample rate indicates the frequency with which a signal is sampled per interval of time. It is measured in sampling values per second. The higher the sample rate the more precise the measurement, and the better the audio quality.
Bit Depth
Bit depth indicates the precision with which an oscillation vibration will be captured. The greater the value, the more accurate is the acquisition and the better is the audio quality.


Sample Format Settings Window