TL:DR; Listen to your work when you want!
Let the computer read your documents so that you can listen to them later.
Boilsoft Ringtone Converter for Mac is powerful ringtone converting software on Mac OS, which helps convert almost all video and audio formats to phone ringtone files such as AMR, M4A, M4R, MP3, OGG and WAV with high speed and excellent quality.
Batch convert WAV, RM, RA, RMVB, M4A, AAC, AMR, AIF, AU, APE, FLAC, OGG, VQF, MP3, WMA, ASF to WMA, MP3, AAC, M4A, AMR, AWB, VQF, OGG, FLAC, APE, WAV formats. Other features include normalization and more.
Audio Encoder can encode/convert any of your audio/video files to any audio format including MP3, WAV, AAC, WMA, FLAC, M4A and AC3. You can also set the basic output quality or set the output bitrate.