DSEE stands for Digital Sound Enhancement Engine, which is a technology developed by Sony to enhance the sound quality of compressed audio files by restoring high-range sound removed by the compression process. DSEE uses complex calculations and predictions to make low-resolution files sound almost like High-Resolution Audio. It reproduces a clear, high-range sound that is often lost. DSEE has different variants, including DSEE HX, DSEE Extreme, and DSEE Ultimate, which have different calculation capacity or prediction power. DSEE is included in Sonys WH-1000XM4 to 1000X series of wireless headphones with noise-canceling function, Xperia smartphones, Walkman, and home theater systems. By activating the DSEE feature, you can hear a rich and natural sound which is almost exactly like the original source. However, the DSEE function is not effective for songs with a file format that is not compressed or songs that are of high bit rate with no treble loss.