What is fernLoudness and what are the benefits for you?


First of all, what does loudness mean for you and your application?

Obviously, music can be loud, interviews might be quiet. People may listen to audio in a noisy or in a quiet environment. On the other hand, low volume parts of the audio may end up not being heard at all – a challenging situation!Audio compression has been introduced to help, but their use can result in a non-natural compression, sounding a bit strange to the human ear. Now, with cutting-edge algorithms, automatic loudness management parameters have been expanded in functionality. Following the EBU R.128 guideline for measurement and multi-band compressors allows for much more precise analysis of the signal. Prediction of the audio over time also helps to get a much smoother output.

This led to our newest development as part of aixtream technology: fernLoudnessFerncast’s proprietary loudness control feature based on EBU R 128.

The Ferncast Team is currently working on the final optimization of our own, proprietary loudness control based on EBU R 128. fernLoudness is a feature, presented as a new PIPE element, which will make aixtream systems handle automatic loudness control according to the parameters the user has defined. This will make manual volume adjustment a thing of the past. According to your requirements, loudness will be regulated by the aixtream system which internally measures and adjusts the dB values of your audio inputs before they are streamed out. You will be able to adjust the values for dB correction ranges, target loudness and timing intervals exactly as your use case requires, so the loudness adjustment is as smooth as you need it to be.

Of course, there are many use cases that will benefit from this kind of automation and optimization. Perhaps the biggest winners are online audio streaming and audio-on-demand applications, which profit greatly from optimized workflows for 24/7 use. Other broadcasting applications will enjoy similar benefits.

Technical Details

Following here we will summarize the technical aspects and advantages of fernLoudness.

The Ferncast loudness control covers the full bandwidth of input dynamics in its measurements and subsequently delivers output signals of a consistent, pre-configured R 128 rated loudness level according to the user’s configuration. After the initial configuration, any necessary adjustments the systems has to make to the loudness levels happen entirely automatic.

It allows sound designers to employ fast frequency selective compression schemes (dynamic processing)to control short-term dynamics as well as long-term level control (loudness processing)to preserve a natural sound – just as it best meets the need and desire of the operator.

 The dynamic processingsupports the following features:

  • Input and output compressors allow limiting and fast full band control.
  • Definition of band edge frequencies allows accurate design of the multi-band filter-bank.
  • Individual compressor configurations can be specified for input and output compressors as well as for the compressor in each individual band of the filter-bank.

In order to take into account human audio perception, the loudness processingcontrol circuitry involves the R 128 loudness measuring to analyze current and long-term audio loudness and is also the basis for all applied level corrections. This way the system prevents situations in which the listeners can make out a jarring loudness adjustment.

For this purpose, all variables of the control can be configured, including time constants, target values and processing limits can be configured.

If desired, the user can receive feedback to better visualize the impact of currently applied correction limitations.

fernLoudness will soon be available for all aixtream products and can be used for every kind of PIPE configuration and use case.

 If you would like to learn more about EBU R 128, please follow this link:


Thank you for your attention and I hope you enjoyed this look into the newest developments at Ferncast and got a better understanding of our commitment to audio excellence and cutting-edge technologies.

Written by Tobias Dornbusch

Tobias studied International Professional Communication at the Flensburg University of Applied Sciences and devotes his skills in Technical Translation and Editing to various tasks here at Ferncast. As our foremost wordsmith he takes care of most kinds of communication, including documentation and support. He ensures that our communication including blogs is both professional and modern.

April 30, 2021

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