TTA is a simple and stable lossless audio data format for real-time compressing of digital music. Free and fully-functional for any use. It has a very simple structure. The TTA file header contains a unique format identifier, which is followed by meta-data block. Meta-data block contains minimal information which is needed for restoring the original stream (including number of channels, count of bits per sample, sample rate and overall number of samples in file, etc.) and ended by a 32-bit control sum. Following that header, we write one or more audio frames. Each frame is ended by a 32-bit control sum; a decoder may start decoding from any frame in the stream. The compressed samples of channels in a frame are located sequentially, as in a simple PCM data format.

This format was originally intended for voice compression and is able to change the bit rates of encoded audio data. AMR is actively used for encoding and decoding voice while its being transmitted over network channels. The format allows one to consider network capacity and adapt it to channel loads. Due to this, the voice quality is practically undiminished.