One sound effect commonly utilized in film production that is often perceived as unrealistic is the sound of punches and impacts during fight scenes. This sound effect is often achieved through the use of foley techniques, where sounds are created and recorded in post-production using various objects to imitate the desired effect. However, these sounds are often exaggerated and do not accurately represent the sounds that would be produced in real life.
For instance, punches that connect in film productions are often accompanied by loud, exaggerated impact sounds. These sounds are designed to make the punches appear more powerful and dramatic. However, in reality, punches do not typically produce such loud noises. This can lead to a disconnect between the visual representation of a punch and the accompanying sound effect, making it appear unrealistic to the audience.
Another example is the sound of breaking glass. In film, the sound of breaking glass is often overly exaggerated, with loud, sharp cracks that are designed to draw the audience's attention. However, in reality, the sound of breaking glass is not always so pronounced and can often be muffled, depending on the type of glass and the surface it is breaking on. This discrepancy between the sound effect used in film and the actual sound of breaking glass can also contribute to a sense of unreality.
These unrealistic sound effects are often used in film production to enhance the audience's emotional experience. However, they can also detract from the credibility of the film and cause the audience to become disengaged. It is important for filmmakers to carefully consider the sound effects they use in their productions and ensure that they are as realistic as possible, while still serving the narrative and emotional goals of the film.
Source: Sound Design in Film: A Practical Guide, by Mark Jonathan.