The importance of sound within Films

Sound within films and TV has developed vastly over time. Producers used to have to include sound effects while they were filming, for example orchestras used to sit on the side of film sets. However now film makes can use 'incredible precision' to create 'fantastically creative and precise effects'.
Some example of sound terms include:
Non-diegetic sound: sound which occurs within the world which is taking place
Diegetic sound: Sound that is not within the role and has been added post-filming
Parallel: Sound that fits with the scene and emphasises what is happening. Eg in Jaws the shark approaching is shown with 'threatening string music'
Post-sychronised sound: Added after filming
Sound bridge: A sound effect or music that runs between a cut. It smooths the join and links the two shots/scenes together

Sound designers:

Jeff Seamster:  Seamster is primarlily a game sound producer. He has worked on titles such as Mortal Kombat vs DC Universe, Caesar IV and Rise & Fall: Civilisations at war. He has worked for companies such as Midway Ga,es, Stainless Steel stoups and Tilted Mill Entertainment. He states that if we all chose our favourite film in terms of sound they would all have distinct similarities: 'strong audio direction and a cohesive audio aesthetic'.
For Seamster he feels that it is important in order for the audience to be able to absorb and interpret what is going on within something. However he urges the importance of developing and adapting sound to stay 'current'. This is in order to keep all audiences engaged rather than following past trends which are no longer valid.

Mel Wesson: Wesson was the sound designer for Christopher Nolan's The Dark Knight and also Batman begins. He had to make sure the sounds of the two shared similarities to keep with the 'continuity' in the audiences 'sub-conscious' 

Sources:

1) www.curriculum-press.co.uk - Understanding and Using sound
2) http://designingsound.org/archives/featured-sound-designers/
3) http://designingsound.org/archives/exclusive-interviews/