In addition to the noises specially recorded in the studio, sounds from noise libraries are often used in video production. There are a lot of such collections. Here are some of them: Sound Ideas Series, Warner Bros Sound Effects Library, The Universal Studios Sound Effects Library and so on.
Noise libraries include collections of sound effects recorded in different places of the world and converted in digital format. Such collections are widely used in areas such as radio, television, cinema, theater, and computer games to create a high-quality, saturated sound background.
In general, collections consist of all types of noise. There are many atmospheres there, even background conversations creating an imitation of a cluster of a certain number of people. You can find, for example, the noise of a restaurant in France, the noise of a market in Germany, etc.
Although the sound recorded on the set already has its own atmosphere, library noises also suitable to create a certain mood. They can be used to enhance the effect or to emphasize an important point of the picture.
Also, the noises from the library are often used in films of historical or action type, for example, for scoring scenes of war. The sound of the shots corresponding to the type of weapon used as a sound background. In cases where it is necessary to create the feeling of watching a film in the past, the sound of a film projector is used. All above in connection with music enhances the impression of the picture.