The term sound design is not clearly defined and can encompass many things. Here I mean

1. the dubbing of sounds (e.g. Foley recording)
2. any sound effects (explosions, alien voices, etc.)
3. the entire sound aesthetic.



The term sound design is quickly associated with sound-powerful blockbusters with various effect sounds such as in Star Wars or nowadays with the transformation sounds of the Transformers.
In fact, this is sometimes not so far removed from a modern corporate production, as can be seen in the excerpt from the REA JET clip.



Computer-generated 2D & 3D animations are mute by nature. As good as they are, the animations only come to life with the right sounds.

Professional sound design is an absolute must-have for advertising.
 As with movies, the quality and directness of the signal play a major role here.