If you are trying to catch ambient background noises for your production, you need to try to use a microphone with a windscreen. Foam windscreens are available for mics for as low as $3 in a variety of colors. The windscreen protects your handheld mic from wind interference as well as dirt and saliva. You also need a recording device, the simplest being your video camera. You want to make sure that you do not use a noise-canceling mic, as this device would not work. A multi-directional mic would work best. You need to make sure that you place it somewhere it could capture the ambient noise, such as away from louder noises, such as cars, air conditioners or heaters, and loud talking or singing.
You can adjust the volume of the recording while producing the final piece, so you want to make it loud enough to catch the desired sounds without distortion. You will probably want to set the volume lower than when trying to catch other sounds. You also will want to set the volume manually, as auto adjustment of sound may provide a lower quality recording of ambient noise.
You may want to record more than one track so that you can mix them for the best quality ambient noise. Stereo or even six tracks may be used for the final production. You may want to get close ups of certain sounds in the environment as well as the general environment that you can adjust for the final recording.
Types of ambient noise you may be seeking to capture are transient sounds, evolving sounds, and speech. Transient sounds are those sounds in the environment that appear quickly and disappear just as quickly. They may be a dog’s bark, the crash of a car wreck, or a face being slapped. When recording the transient sounds of an environment, you may have to record much longer than you normally would to capture these transient sounds that are part of the environment.
Evolving sounds are those that come on slowly and leave slowly, if ever. Examples of evolving sounds are the clatter of a train coming closer, the song of birds, or the waves rolling into shore. Even with evolving sounds, you need to make sure that you record longer to capture the source of the noise from a distance and then close-up. The sound is very different, and most realistic when the appearing and waning of the sound is captured.
The third type of ambient noise is speech. In some works, the sound of conversation in the background is necessary to make the piece feel realistic. Rarely are scenes in cities and busy places lacking talk or conversations in the background. The key to capturing speech is keeping it low enough that it does not dominate the scene that you are trying to capture. Speech could capture a scene or distract from the scene if you are not careful when finalizing your production. You want the speech sounds in the background, and not the forefront.