Sony MDR-NC300D Product Information page 14

Three sound modes
Three sound modes suited to the characteristics of the music source ensure easy listening in any noise environment.
 NORMAL:
This mode maximizes the merits of the noise canceling headphones to produce clear, natural sounds.
 BASS:
This mode boosts the bass sounds that give punch to modern dance music.
 MOVIE:
This is the sound mode suited to an AV sound source with wide dynamic range, such as a
movie.
Compression processing increases the volume of quiet sounds such as conversation and
reduces the volume of loud sounds like explosions, thereby adjusting the overall volume to
a listener-friendly level.
Moreover, dialog is made much easier to hear by slight emphasis of the core midrange
frequency, ensuring clear, natural sounds even on a train or plane or in other noise
environments.
1