Have you ever noticed that some audio files play too quietly while others blast at full volume? Constantly adjusting the volume can be frustrating, whether listening to music, watching a video, or editing a podcast. That's where audio normalization comes in.
But what exactly does it do to your audio file?
In this blog, we'll break it down and explore the two main methods of normalizing audio—helping you decide which one is right for you!
What Is Audio Normalization?
Audio normalization adjusts the overall volume of a recording.
It's the process of adjusting the gain or amplification of an audio recording to reach a target volume level. Audio normalization applies the same change to all samples, making the entire track uniformly louder or quieter—including dialogue, background noise, breaths, and other sounds.
The goal is to ensure the audio plays at a steady, comfortable level without sudden jumps in volume.
What Is a Sample?
In digital audio, a sample is a tiny unit of recorded sound.
When an audio recorder captures sound from a microphone, it converts it into digital data by taking thousands of snapshots—called samples—every second.
For example, at a sample rate of 48 kHz, the recorder captures 48,000 samples per second to accurately represent the sound wave. Since normalization applies a uniform adjustment to all samples, every part of the audio gets louder or quieter by the same amount.
Types of Audio Normalization
There are two main types of normalization: peak normalization and loudness normalization.
Peak Normalization
Peak normalization adjusts an audio recording based on its highest peak. It identifies the loudest point in the waveform and scales the entire audio file so that this peak reaches a defined target level.
For example, if you set the normalization target to -1.5 dB, the software calculates the difference between the highest peak and this target. Then, it applies the same adjustment to all samples in the recording. The method is straightforward and effective for making an audio file louder or quieter while preserving its dynamics.
Challenges with Peak Normalization
While peak normalization can make an audio file louder, it doesn't always guarantee a consistent listening experience. The main challenge is that it only adjusts based on the loudest peak, without considering how humans perceive loudness.
For example, if an audio file has a single loud transient—such as a sharp sound or a sudden noise—it may prevent the overall volume from being raised significantly. On the other hand, a continuous sound at the same peak level will seem much louder to the human ear. This means two files with identical peak levels can still sound vastly different in loudness.
That's why loudness normalization is often a better choice.
Loudness Normalization
Loudness normalization adjusts audio based on perceived loudness rather than just peak levels. Instead of focusing on the highest amplitude, it calculates an average loudness level, making adjustments accordingly.
This method uses advanced measurements like RMS (Root Mean Square) and industry standards such as EBU R128 or ITU-R BS.1770 to reflect how the human ear perceives sound. These standards account for variations in volume—such as quiet dialogue or background music—ensuring that silent passages don't drastically affect the overall loudness measurement.
By using loudness normalization, you can achieve a more balanced and consistent audio experience, which is crucial for podcasts, streaming content, and professional audio production.
Measuring Loudness
Loudness normalization relies on specific measurement methods to ensure a balanced audio experience. One of the key metrics used is Loudness Units Full Scale (LUFS), which is part of the ITU-R BS.1770 standard. This method calculates the perceived loudness of an entire audio file rather than just its peak levels.
For example, if an audio passage has an overall LUFS of -19, it means the loudness is measured at that level across the file. However, if silence is introduced—such as pauses in a dialogue scene—the RMS (Root Mean Square) loudness can drop significantly, even to negative infinity.
In contrast, the LUFS value remains relatively stable. This is why LUFS-based normalization is more effective for maintaining consistent volume across different types of audio content.
Which Normalization Method Should You Use?
- Peak Normalization – Best for quick volume adjustments but doesn't guarantee a smooth listening experience.
- Loudness Normalization (EBU R128, ITU-R BS.1770) – Ideal for professional audio, ensuring consistent volume across different platforms.
Audio Normalization Software
The easiest way to normalize audio is by using an online tool. Web-based solutions provide quick and efficient adjustments without the need for installation.
A great option is the Audio2Edit's - Normalize Audio tool, which allows you to balance audio levels effortlessly, ensuring a consistent and professional sound.
Find out more: How to Normalize Audio Online
In Conclusion
Audio normalization is a crucial step in ensuring a consistent listening experience. While peak normalization adjusts volume based on the highest amplitude, it doesn't always result in uniform loudness. Loudness normalization, on the other hand, accounts for human perception, making it the better choice for videos, podcasts, and streaming.
By choosing the right normalization method, you can ensure that your audience enjoys clear, balanced, and professional-quality audio, without having to constantly adjust the volume.
Want to normalize audio easily?
With Audio2Edit, you don't need audio expertise. Just upload your file, choose a setting "Automatic Normalization", and let the tool handle the rest!