Many mobile phones can record and use AMR audio files, which are especially designed for spoken audio. AMR to MP3 Converter can convert these to MP3 and MP3 to AMR.
This is an incredibly simple application. There are no options for things like choosing bit rates or quality, simply two tabs, one for converting to AMR and the other to MP3. Conversions are quick, but we found a noticeable drop in quality whichever direction the conversion was done.
AMR to MP3 Converter is useful for people with older phones, as it can be used to create compatible ring tones from any MP3. It's a shame that there aren't any editing features, which makes this as basic a converter as you will find anywhere.
AMR to MP3 Converter is a functional tool for making AMR files for phones, but the lack of options and quality choices mean it's not much use for anywhere that needs better sound fidelity