Final answer:
Studios used Foley artists, the photoelectric effect, and sound designers to avoid the cost of sound.
Step-by-step explanation:
In order to avoid the cost of sound, studios in the early/middle of the 20th Century used various techniques. One method was the use of Foley artists, who created live sound effects using objects and a Foley table. Another technique was the use of the photoelectric effect to create sound in movie theaters. Additionally, studios relied on databases of recorded sounds and the skills of sound designers to create accurate and consistent sounds for their productions.