1)   OJOsoft M4A Converter 1.5.3.0218
It can convert M4A files to MP3, MP2, WMA, OGG, MP4(audio only), AAC, AC3, WAV. This converter not only converts M4A files to audio formats , but also supports converting video and audio files to M4A, AAC, MP4(audio only).

 2)   Abcc Free Music to MP3 AMR Converter 4.0
Abcc Free Music to MP3 AMR AAC OGG Converter provides an easy and completed way to convert between MP3, AAC, AC3, AMR, M4A, OGG, and WAV audio, such as MP3 to AAC, AAC to MP3, OGG to AMR, and M4A to MP3.

 3)   Abcc Free MP4 MP3 to AMR Converter 3.1
Abcc Free MP4 MP3 to AMR Converter is all-in-one and powerful software for audio conversion. It can convert audio files between all popular formats including MP3, AAC, AC3, AMR, M4A, OGG, and WAV. In addition, it can extract audio files from video.

 4)   Abcc Free All media to MP3 Converter 4.0
Abcc Free All media to mp3 Converter offers easy, completed ways to convert all media including all popular vide and audio files to audio format. Convert between MP3, AAC, AC3, AMR, M4A, OGG, and WAV audio files.

 5)   Cool Free Audio to OGG Converter 5.1
Cool Free Audio to OGG Converter is an all-in-one and professional OGG audio conversion software. With Cool Audio to OGG Converter, you can convert almost all media including AVI, WMV, MPEG, MP4, ASF, VOB, 3GP, iPhone, MOV and FLV and MP3, AAC, AC3.