This is possibly the best free software for audio editing
Audacity is a free, easy-to-use audio editor and recorder for Windows, Mac OS X, GNU/Linux, and other operating systems. You can use Audacity to:
Record live audio.
Convert tapes and records into digital recordings or CDs.
Edit Ogg Vorbis, MP3, and WAV sound files.
Cut, copy, splice, and mix sounds together.
Change the speed or pitch of a recording.
And more! See the complete list of features
Listed below are nine resources starting with a lesson plan I have edited, the other nine are audio clips that go with the lesson plan. You can download all ten resources individually or download the zipped folder containing all resources at the bottom of this table.
The lesson plan will need to be edited with your network folder locations.
This is suitable for all key stages upwards of KS2