Whatever

Examples of the different audio recordings, one for each the different formats: 

Saved as test2.zip or test2.tgz each about 8.4MB, test2.tar about 10.4MB.

Or, individually:

• test2.wav WAV Microsoft WAVE 
• test2.aiff AIFF Apple AIFF
• test2.flac FLAC Free Lossless Audio Codec
• test2.mp3 MP3 MPEG-2 Audio Layer 3
• test2.mp4 MP4 MPEG-4 Part 14 Audio File
• test2.m4a M4A MPEG-4 Part 14 Audio File (same as MP4)
• test2.aac AAC MPEG-4 Part 14 Audio File (same as MP4)
• test2.ogg OGG Ogg Vorbis

These were recorded by me using the Audacity sound editor on Ubuntu Linux.  These are samples provided for free to use in your testing or for whatever other purpose you wish to use them for — i.e., each sample is public domain.

Examples of the same audio recording saved in the different formats: 

Saved as test1.zip or test1.tgz each about 7.5MB, test1.tar about 10MB.

Or, individually:

• test1.wav WAV Microsoft WAVE 
• test1.aiff AIFF Apple AIFF
• test1.flac FLAC Free Lossless Audio Codec
• test1.mp3 MP3 MPEG-2 Audio Layer 3
• test1.mp4 MP4 MPEG-4 Part 14 Audio File
• test1.m4a M4A MPEG-4 Part 14 Audio File (same as MP4)
• test1.aac AAC MPEG-4 Part 14 Audio File (same as MP4)
• test1.ogg OGG Ogg Vorbis

These were recorded by me using the Audacity sound editor on Ubuntu Linux.  These are samples provided for free to use in your testing or for whatever other purpose you wish to use them for — i.e., each sample is public domain.