WMA is a widespread licensed audio stream compression format. Created in 1999 by Signal Processing Group, a member of the IT giant Microsoft. Initially, this company created WMA as a competitor to the popular MP3 format. The name WMA is an abbreviation for Windows Media Audio. Among the advantages of this format is the support of almost all Windows systems and devices, as well as the similarity in characteristics and quality with MP3 files. It is believed that a compressed WMA audio file with a bit rate of 160 kbit / s is fully consistent with the quality of an MP3 file with a bit rate of 256 kbit / s. Today, even Apple devices support the WMA format.
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.