Sound recordings are the stepchildren of video production. Sound is part of film, but too often plays the supporting role. At the same time, there are few means that can shape a video more cost-effectively. In this article you will find a guide to professional audio recording on the film set.
The recording of the sound has a decisive influence on what is commonly called the image impression. To get the best possible results from your sound recordings, you need to follow 17 rules when filming. Our guide explains in a clear way all the important points when recording audio tracks on the film set.
The human hearing organ recognizes loudness only as a deviation from preceding or following sound information. Therefore, the sound pressure level is used to describe this acoustic information. It is expressed in the relative value decibel (dB).
But our hearing is also highly adaptive: it adjusts its sensitivity to the prevailing sound level. Therefore, sounds in the background of a video recording can be pushed back from consciousness. When the ear is exposed to a stimulus over a certain period of time, it becomes accustomed to the continuous sound. It begins to fatigue and the audio information is increasingly perceived as quieter, or not audio information at all.
The frequency – – defined as Hertz (Hz) – – indicates the number of oscillations of a sound wave per second. The human ear can perceive sound in the frequency range from 20Hz to 20kHz. Our hearing is most sensitive to sounds in the frequency band from 3 to 5 kHz. This is why this frequency range is particularly important for the sound mixing of dialogues or videos, where intelligibility is of prime importance.
There is a link between the sound pressure level and the frequency: sinusoidal tones with a constant sound pressure level and changing frequency are perceived by people as being of different loudness. Similarly, a technical change in level is perceived by the ear as a change in sound.
Every tone produced by an instrument or the human voice consists of fundamental and harmonics. Harmonics and fundamentals are both always sinusoidal. The individual sinusoidal oscillations add and subtract to form a so-called envelope curve. The fundamental determines the pitch, the overtones define the character of the sound. So whether we hear a piano or a saxophone always depends on the respective overtones.
1Sound is less forgiving than images
The most important point to keep in mind when dealing with sound recordings has to do with the way our brains process sound information. Unlike images, there is a much smaller tolerance for error in the perception of sound.
Most of the time we can’t even tell in detail what’s wrong with the sound track. But instinctively we feel that a mistake must have happened in the sound recording: the track sounds wrong because it does not sound as the environment presented by the picture does in reality. Too much reverb or a too dry sound and minimal deviations are enough to trigger irritation in our subconscious.
So how do we get perfect audio when shooting a video?
2Soundtrack also needs to be planned
When planning a video, a concept for the sound is also part of the pre-production. Making sound recordings just on the side leads to a random result. Coincidence is the opposite of professionalism.
Often it’s enough just to be aware of the sound in the first place. And to ask oneself in the context of preproduction: how are the sound recordings made in a purely practical way for this shot or for that scene. A storyboard or shooting board helps just as much with this as it does with the planning of the respective film images.
Sound people never have the superior status on set that a camera person has. Nevertheless, they must not be prevented from carrying out their work in practice. They, too, have a right to plan ahead, because this is the only way they can perform their function professionally.
3Work with the microphone of the camera only in case of need
It’s no secret among professionals: a video camera’s microphone is designed only as a backup. If you are on a report with your camera and your handheld mic is defective, you still have the sound recording of the camera mic as an emergency solution.
Otherwise, i.e. always, an external microphone is used!
This is also because many camera manufacturers, aware of the reserve function of the camera’s own microphone, focus their attention on the image capture unit when developing their cameras. Thus, the best possible microphone for sound recording is rarely found on the camera. It’s the cheapest model.
4An external microphone works wonders for sound recordings
The moment you are thinking about buying your first camera, you should also take into account one or two external microphones.
Good sound recordings will only be possible with an additional external microphone! For very little money, you can find affordable camera accessories that will make a world of difference to the sound of your video recordings.
5Each microphone picks up sound differently
Not all microphones are created equal. Depending on the type of sound recording, you will choose a microphone with different specifications.
- A microphone can be distinguished according to its mode of operation or its directional characteristic.
- A distinction can also be made according to the type of interface(radio link, XLR, jack).
- The polar pattern describes which area of the room is picked up by the microphone. An omnidirectional microphone picks up sound evenly from all directions (called an omnidirectional microphone). The opposite of this, the directional microphone, records sound only at the exact point to which it is pointed.
- Directional microphones are particularly well suited for dialogue and voice recordings. These include cardioid microphones, which capture sound in a kidney shape: Sound waves from the background are not picked up, lateral noises are only attenuated.
- According to the way they work, a distinction is mainly made between condenser microphones (divided into two subgroups: large and small diaphragm microphones) and dynamic microphones (again with two types: moving coil & ribbon microphones).
Overview of microphones and accessories for recording sound in videos (from left to right): radio link, omnidirectional microphone, directional microphone, cardioid microphone, dynamic microphone, windscreen, sound angel)
© Photos by the respective manufacturers
There are all-purpose microphones. But not one that is equally good for all purposes. Each part has its advantages and disadvantages. The better a microphone is suited for one type of sound, the weaker its performance for a different task.
6You can’t do it without headphones
When recording sound, you can’t avoid checking the sound quality live. It is only possible with the real hearing impression, which again only a good pair of headphones can give you.
Besides the camera and microphone, headphones are the third piece of equipment you can’t do without when recording sound. To do this, test a few different models that fit your price range.
Remember that the headphone jacks, like the microphone jacks, must match the interfaces to your camera model.
7Sound angel or lapel microphone?
It is impossible to imagine feature film productions without the Ton-Angel. It’s at least as much a cliché of a real movie as the director’s hatch.
The tang brings the microphone into an ideal proximity to the sound source when recording sound. However, their use in shooting looks much easier than it is in practice. Not only must the sound angel be out of the camera’s view, it must also follow movement and not cast shadows on the actors’ faces.
For these reasons, in many types of films, filmmakers choose to record sound with a lapel microphone (also known as a lavalier microphone).
Modern clip-on microphones are so small that they hardly interfere with the picture. At least as long as it’s not short films or feature films where a microphone is perceived as a foreign object.
When using lavalier / clip-on microphones, care must be taken to ensure that neither another item of clothing (jacket, collar, tie) nor the chin, neck or hand of the wearer come into contact with the microphone! Otherwise, noise will be generated which may render the entire sound recording unusable.
8Note the audio level: Input is output
For sound recordings, the sound level must be correct. So simple and so difficult. Again, input equals output.
You can level the sound during recording either manually or automatically with software support. Professionals choose a middle ground of three variables to achieve optimal recording quality:
- the distance of the microphone from the source of the sound,
- the manual control of the sound carrier
- and the use of software.
In many cases, the sound is monitored during recording and the automatic leveling is manually adjusted where desired.
9Silence is part of the sound
No shooting, no video recording and no film may enter the editing room after shooting without at least 10 seconds of “silence” being supplied as an audio track for each individual sequence.
Absolute silence does not exist in any filming location. Always and everywhere there is an ambience in the sound. This is why it is absolutely necessary to record it separately as a sound, because only in this way can the respective atmosphere of a scene be placed consistently under all the other sounds later in the edit.
Sound and noises also play an important role in the montage because they connect the individual shots and make transitions seem more fluid.
10Attention when recording dialogues
A particular challenge is the inclusion of dialogue. Basically, every sound engineer and every sound assistant is faced with a difficult and even contradictory situation here:
- First, the dialogue should be recorded as true to life as possible. People who speak to each other often consciously or unconsciously interrupt each other at the end of a sentence. It doesn’t have to be words that overlap and overlap in tone. Breath noises, body noise or a glass being put down are all part of life, but irrevocably spoil a clean dialogue recording.
- Secondly, as already outlined, for the audio mix the technical crew would like to get all the sound recordings separated as much as possible, so also the dialogues as monologues if possible.
The people responsible for the sound recordings therefore have only two options:
- You can ask the actors to speak their lines individually, which largely destroys authenticity in a fight scene. If only because speech tempo and expression are almost always different from a 2 scene.
- Or they “interlace” the dialogues irrevocably already during the sound recording and thus take away part of the creative design possibilities of the mix.
Which of these two paths is chosen for the production must be agreed with the director, producer and the person responsible for post-production.
11Proximity to the sound source means quality
Sound recordings are almost always post-processed in audio post-production in professional film and video production. The age-old but highly proven film principle of “input equals output” also applies to film sound.
What does that mean? Quite simply: where the original sound is not optimal, a good quality sound mix cannot be created from it – or only with a great deal of effort, money and trouble.
That’s why when you record sound, you want to record the original sound in the best possible quality. To do this, the microphone must be as close as possible to the sound source.
12Isolate sound during recording
But it is not only the distance to a sound source that determines professional sound recordings. It is also important to record the individual sounds as isolated as possible during the recording.
The cleaner and more self-contained a sound is recorded, the better it can be processed later in the sound mix.
Overlaps of sound, reverberation or volume are simulated in sound editing with a mouse click. The same cannot be said of the reverse: isolating sounds or even voices from a digital audio recording rarely succeeds in satisfactory quality.
13Avoiding noise during sound recording
Many sound recordings are the victim of noise, which was not noticed during the shooting and therefore could not be prevented.
The right choice of microphone helps to minimize the noise level of a busy street in the background of the filming location. It is better to have no noise at all. This point leads us back to planning, where sound must also have a say in the choice of locations.
14Do not forget a windbreak
In every sound equipment belongs not only an external microphone, but also a windscreen. A windscreen prevents noise from wind and gusts of wind. Because the corresponding protective covers often have a fur-like structure, they are sometimes called “dachshund fur” on film sets in German-speaking countries.
15Control the sound before, during and after recording
Having to throw away a scene because of poor sound recording is the nightmare of many directors. Because repeating a shoot is usually not an option because it’s too expensive or impossible to schedule.
The only thing that helps against such horror scenarios is the control of the sound quality before, during and after the sound recording. If you don’t control, you expose the quality of your video to unnecessary risks.
16Rights on the sound: Attention to personal rights!
There are not only rights to the image, you can also have a legal claim to your own sound / sound image of your voice. You know this from music, where it’s usually about copyrights. With sound recordings of people, however, the legal aspect is often completely forgotten! This is especially true for movies that don’t have a feature story. Sound rights, however, include not only copyright but also personal rights.
The legal regulation on the right to one’s own sound is unambiguously regulated in Germany: Sound recordings made by someone without consent are a criminal offence under § 201 and § 201a of the German Criminal Code (StGB) respectively.
Not only the recording, but also the subsequent use or making available of a sound recording to other persons, whether by publication or disclosure, is punishable under the Criminal Code (in addition to the actual sound recording).
17Edit audio track
Good sound recordings are always characterized by the fact that they are carefully post-processed. Just as video recordings are optimized for color in Color Correction, the sound in the mix is also tailored precisely to the respective purpose and the desired creative effect.
Almost every editing software today allows you to do extensive sound editing. Many of these video editing programs are even available for free.
This article was automatically translated into English using AI. If you would like to help us improve the quality, we would be happy to hear from you.