Allows private listening enjoyment of multi-channel music or movie sound, including Dolby Digital and DTS Digital Surround, through ordinary headphones. Yamaha DSP and HRTF technology (explained on right) make it possible. All the listener needs to do is connect a pair of headphones to the DSP-AZ1 and they will enjoy an accurate simulation of 5.1-channel surround sound in complete privacy. They can even select from among the many CINEMA and HiFi DSP programs to vary the sound field. Ideal for late night listening when you donâ€™t want to disturb others, or if other noises are disturbing you.