AMR is a sound file format with a specific focus. Created a long time ago, before the advent of MP3. some sources call the developer Ericsson. The name of the format is an abbreviation for Adaptive Multi Rate. Sound files of this format are intended for mobile devices and in GSM cellular networks. Using this format provides a small file size due to the technology of signal coding in the speech frequency range. Effectively compressing audio recordings of human speech makes this format often used in voice recorders on mobile phones, for voice recordings, and for MMS messages.
WAV (or WAVE) is actually the first full-fledged audio format with good sound quality. It was developed quite a few years ago by the joint efforts of Microsoft and IBM. Sometimes this format is even called “Audio for Windows,” because it is the standard for storing audio stream for a traditional Windows desktop computer. Full name - Wave Audio File Format. The short name is derived from the English word wave ("wave"). The peculiarity of this format of digitized audio stream is the lack of compression. WAV files take up too much space, but it is ideal for storing high quality files in their original form.