You’d be forgiven for reading the title of this article and thinking ‘What else is there to understand about audio loudness?’. The general interpretation of loudness is simply how loud something is, but when it comes to creating professional content, it’s not quite as straightforward as that.
In this article, we’ll look at the difference between loudness, level and volume in audio, and why it’s important to distinguish these terms from one another. We’ll also explain how considering your audio levels throughout the creative process will help you to produce more professional content.
The key technical terms used in this article are highlighted in bold. We’ve also compiled them into a glossary at the bottom of the article for your reference.
What is Loudness in Audio?
Audio loudness refers to an individual’s perception of how loud a piece of audio is. There are many factors that can affect the perceived loudness of audio, including frequency content, duration, and of course the volume at which the audio is played.
Volume vs Level vs Loudness
While many people use these terms interchangeably, technically, volume, level and loudness are not the same thing. While loudness refers to the subjective perception of how loud a piece of audio is, level and volume are tangible measurements that can be expressed with specific figures.
Volume is the measurement of how loud a piece of audio is in the real world, and can be measured in Sound Pressure Level or SPL. Level refers to an audio signal’s specific numerical value at any given point, whether that’s during recording, processing or playback.
Why are Your Audio Levels Important?
Now that we’ve covered the terminology surrounding audio loudness, you might be wondering why it’s so important to get your levels right when creating content.
To Improve the Quality of Your Audio
When recording audio, it’s important to capture audio at the correct level, as this will help to ensure you achieve the best possible audio quality. If you record too quietly, you will need to increase the level of your recording later on. But as you increase the level of your primary subject, you also increase the level of all other noises within the recording.
This might include environmental sounds such as road traffic, electrical hums, wind noise or other people speaking in the background. For this reason, it’s important to record your subject at the appropriate level, thus avoiding making any drastic level changes later on.
By the same token, you shouldn’t record too loud either. This may result in clipping, whereby an audio level exceeds your recording equipment’s ability to capture audio accurately. Clipping can cause your audio to distort, resulting in an unpleasant listening experience for your audience.
To Ensure Your Video Volume Compares to Other Content
Have you ever been scrolling your socials when a ridiculously loud video has jumped out at you? Or perhaps a video’s audio was far too quiet and you needed to turn your phone volume right up to hear it.
In both of these cases, the audio level has been incorrectly managed at some point during the video’s creation. This demonstrates why it’s not only important to ensure your audio levels are correct when recording, but remain correct at the point at which you publish your content too.
How to Set, Measure and Adjust Audio Levels
By now, you should hopefully understand the importance of getting your audio levels right, but how can you set, measure and adjust your levels for the most professional results?
Record at the Correct Level
As we’ve already discussed, it’s important to start by capturing your audio at the correct level if you want to achieve the most professional results. Positioning your audio source or subject at the correct distance from your recording equipment is a great way to control your recording level.
Record too close and your recording may be too loud, which could cause the signal to clip. Record too far and your recording will be too quiet, which may mean that you capture unwanted external noises too. If you’re using a phone, adjusting the recording distance may be your only method of controlling the level of your audio.
If you’re using more advanced recording equipment, such as a microphone, field recorder or camera, you may be able to adjust the recording level. This is likely to be through the means of a gain control. Gain allows you to amplify a signal before it is processed, unlike volume, which is used to amplify a signal during processing or playback.
If possible, use your microphone position and gain controls to set your recording level to be as loud as possible without the signal clipping. Try taking some test recordings at a range of distances until you find the right recording configuration.
Measure Your Levels with an Audio Meter
No matter which video editor or content creation tools you’re using, they should have an integrated audio level meter. Generally, an audio meter will show the level of the left and right channels on a range of -∞ to +6dB. Within the digital domain, an audio level of negative infinity equates to complete silence, and anything above 0dB results in clipping.
As a rule of thumb, your raw audio recordings should sit somewhere between -18dB and 0dB. This represents a Goldilocks zone, where you don’t need to increase the levels so much that you introduce unwanted background noise, and won’t clip your audio signal.
If your audio recording is below -18dB or above 0dB, it may be best to re-record it at the appropriate level if possible. The only exception to this is if you’ve recorded below -18dB in an extremely quiet environment, in which case increasing the level of your audio to the desired volume may be possible.
Increase the Audio Level Manually
Once you’re happy that you’ve recorded at the correct volume, you can increase the level of your audio within your editing software. The aim here is to get the loudest part of your audio as close to 0dB as possible without ever actually exceeding 0dB, as this will cause your audio signal to clip.
Apply Normalisation
As well as audio level meters and volume control, most video editing software should have the means to normalise your audio during processing or export. This refers to the process of automatically increasing an audio signal’s level until the loudest point reaches a predefined target. The predefined target depends on the specific platform. For example, YouTube, TikTok and Facebook all have different normalisation targets.
Normalisation is designed to maintain a more consistent audio volume between videos, and so most social media platforms apply their own normalisation when you publish a video. Many video editing and content creation tools also offer some form of normalisation, which gives you an idea of how your video will sound when you upload it to your socials.
One downside of normalisation is that it doesn’t solve the problem of inconsistent audio levels. If your video contains both quiet and loud sections, the level will be set according to the loud parts. This means that the quieter parts will remain quiet, which may make them difficult to hear. The image below provides a visual representation of this issue.
Apply Dynamic Compression
Some more advanced video editing software will also let you apply dynamic compression to your signal, which can help to overcome the downside of normalisation mentioned in the previous section.
Dynamic compression is when the loudest parts of a signal are turned down, resulting in a more consistent overall volume. This is particularly useful when there is a large difference between the levels of the quietest and loudest parts of an audio recording.
The image above demonstrates the difference between the normalised audio and the compressed and normalised audio. The compressed and normalised audio has a much more consistent overall level, which results in a better listening experience for your audience.
Glossary
This glossary contains all of the key technical terms covered in this article.
Clipping
When an audio signal exceeds 0dB within the digital domain. Clipping can cause an audio signal to distort, resulting in an unpleasant listening experience.
Distortion
Can occur as a result of clipping, and is characterised by unpleasant fuzz or noise within the audio signal.
Dynamic Compression
When the loudest parts of an audio signal are turned down in volume, thus reducing the difference between the quietest and loudest parts of an audio signal.
Gain
A means of amplifying the level of an audio signal before any processing is applied.
Level
An audio signal’s specific numerical value at any given point, such as during recording, editing, processing or playback.
Loudness
The subjective perception of how loud a piece of audio is.
Normalisation
The process of automatically raising an audio signal’s volume until the loudest part reaches a predetermined level.
Volume
The scientific measurement of how loud a piece of audio is.
