Audacity editing software
"Audacity is free software, developed by a group of volunteers and distributed under the GNU General Public License. Free software is not just free of cost (like 'free soda'). It is free as in freedom (like free speech?). Free software gives you the freedom to use a program, study how it works, improve it, and share it with others.
Programs like Audacity are also called open source software, because their source code is available for anyone to study or use. There are thousands of other free and open source programs, including the Mozilla web browser, the OpenOffice.org office suite, and entire Linux-based operating systems."
We highly suggest this software as the means to produce your program. Not only is it simple and efficient, it's free! The latest distribution can be found at http://audacity.sourceforge.net.
Once you have downloaded the appropriate package (for example, the Windows installer version for MS / Windows, or the OSX installer version for OSX) proceed to run the program simply by double-clicking on the install icon.