What is a .AMR file?
AMR is a speech-optimised audio format used for voice recordings on phones.
- Did you know
- AMR was adopted in 1999 as the standard voice codec for GSM mobile networks.
- AMR uses the ACELP technique and was chosen by 3GPP as the standard speech codec for GSM and later mobile networks.
- Its name, Adaptive Multi-Rate, refers to its ability to switch among several bitrates from about 4.75 up to 12.2 kbps as conditions change.
- The codec samples speech at 8 kHz and targets the roughly 300 to 3400 Hz band of the human voice, so it sounds poor on music.
- A wideband cousin, AMR-WB, widens the captured frequency range to deliver the clearer “HD Voice” quality on newer phone calls.
- What Analyser shows you
- Inspect the waveform, spectrogram, codec, bitrate, channels, and tags of MP3, WAV, FLAC, M4A, AAC, OGG, and Opus audio.
- Open a .AMR file
- Drag a .AMR file onto the Analyser home page (or tap to pick one). It opens entirely in your browser - nothing is uploaded, there is no account, and it works offline once installed.