.AMR File Extension
File TypeAdaptive Multi-Rate Codec File
This file is saved in a binary format, which requires a specific program to read its contents.
What is an AMR file?
An AMR file is an audio file saved in a compressed audio format developed by Ericsson. It is used by many 3G cell phones for voice recordings such as MMS messages. AMR files incorporate the Algebraic Code Excited Linear Prediction (ACELP) algorithm, which is designed to efficiently compress human speech audio.
NOTE: AMR files may be saved in either the AMR-NB (Narrowband) or AMR-WB (Wideband) format. Wideband audio supports a broader frequency range and therefore provides better sound quality.