The background score of horror movies, tends to use digital sound effects these days, rather than original sound from instruments like a cello, drum or keyboards.
Music impacts the part of the brain that controls the link between sound, memories and emotion, the medial pre-frontal cortex, says the National Institutes of Health. Listening to music can soothe the emotions. A study published in the December 2009 journal Pediatrics found that premature babies demonstrated an increased rate of weight gain when they were exposed to music by Mozart. The music soothed the babies, reducing their resting energy expenditure. Researchers speculate that the weight gain seen in premature babies who are exposed to Mozart results from this lower energy expenditure.
In May 2006, the Journal of Advanced Nursing reported that people who listen to music experience less pain and lower levels of depression and disability related to pain than those who don't listen to music. This indicates that music can effect the brain by lifting the mood and alleviating the perception of pain.
Thus, if various sounds and their frequencies carry the capacity to inhibit or produce a specific emotion in our brain, does Horror movie JUMP SCARES use this technique to make sure we DO get scared, even if the plot, acting and other factors have a fair chance of failing?
In the early days of film and radio, foley artists would add sounds in realtime or pre-recorded sound effects would be played back from analogue discs in realtime (while watching the picture). Today, with effects held in digital format, it is easy to create any required sequence to be played in any desired timeline.
In the days of silent film, sound effects were added by the operator of a theater organ or photoplayer, both of which also supplied the soundtrack of the film. Theater organ sound effects are usually electric or electro-pneumatic, and activated by a button pressed with the hand or foot. Photoplayer operators activate sound effects either by flipping switches on the machine or pulling "cow-tail" pull-strings, which hang above. Sounds like bells and drums are made mechanically, sirens and horns electronically. Due to its smaller size, a photoplayer usually has less special effects than a theater organ, or less complex ones.