Sound design is the process of specifying, acquiring, manipulating or generating audio elements. It's used for various creative projects such as film making, television production, sound recording, post-production, video game development and much more. Sound design usually involves editing previously recorded audio by adding sound effects or dialogue.
Since prehistoric times, people have put on dances and plays and used sound to evoke emotions and create different moods. At it's earliest, it was used for religious practices and services. In ancient Japan, theatrical performances took place in shrines with music and dancing.
Plays were performed in medieval times in theatre's that used music and sound effects to enhance the performances and evoke emotions. In Elizabethan theatre, sound effects and music were produced off stage using instruments like bells and whistles. They also wrote cues for the music and sound effects so they were heard at the right moment.
The first use of recorded sound in a theatre was a phonograph playing a baby's cry in a London theatre in 1890.
Digital audio technology helped sound design evolve rapidly in the 1980's and 1990's. Computerised theatre sound design systems were seen as essential for live shows at Walt Disney World, This led to Disney opening it's MGM Studios park in 1989.
More recently, the World Wide Web has allowed sound designers to acquire source material quickly, easily and cheaply. Now a designer can download and create more believable sounds due to technological advances. People can create professional sounds from their own homes, they can make them on their mobiles, laptops and tablets. You can use simple speakers, microphones and headphones which is much cheaper and quicker than renting or buying specialist equipment or booking studio time.