A brief history first.
“Loudness war” or “loudness race” is the popular name given to the trend of increasing audio levels in recorded music since the early 1990s, which many critics believe reduces sound quality and listener enjoyment. Increasing loudness was first reported as early as the 1940s with respect to mastering practices for 7″ singles. The maximum peak level of analog recordings such as these is limited by varying specifications of electronic equipment along the chain from source to listener, including vinyl record and cassette players.
With the advent of the Compact Disc (CD), music is encoded to a digital format with a clearly defined maximum peak amplitude. Once the maximum amplitude of a CD is reached, loudness can be increased still further through signal processing techniques such as dynamic range compression and equalization. Engineers can apply an increasingly high ratio of compression to a recording until it more frequently peaks at the maximum amplitude. In extreme cases, efforts to increase loudness can result in clipping and other audible distortion. Modern recordings that use extreme dynamic range compression and other measures to increase loudness therefore can sacrifice sound quality to loudness.
In order to achieve these super-high levels, the music has to be squashed up against the digital maximum level “ceiling” – reducing the difference between the peak and average levels in the music. In the process, the contrast between loud and soft moments (often referred to as the dynamic range) is dramatically reduced.
The “Loudness War” is built on the idea that “louder is better” but recent research shows there is no connection between “loudness” and sales, most people don’t notice loudness when comparing songs and most listeners just turn loud music down!
Broadcasting is also a participant in the loudness war. Competition for listeners between radio stations and competition for clients between recording studios has also caused a loudness “arms race”. Loudness jumps between broadcast channels and between programs within the same channel, and between programs and intervening adverts are a frequent source of audience complaints.
Music Loudness Normalization
With music sales moving towards file-based playback, digital downloads and away from CDs, there is a possibility that the loudness war will be blunted by normalization technology such as ReplayGain and Apple’s Sound Check. Most cloud-based music services perform loudness normalization by default and may reduce the market pressure to hypercompress material.
Most popular personal music players also have loudness-normalization options, like the Sound Check function on Apple’s iPods and iPhones, and on computers when using their iTunes playback software, to maintain consistent loudness when music is played in shuffle or playlist modes.
Loudness normalization means there is no advantage in producing ‘loud’ CDs or downloads, because the perceived loudness will be the same for everything. The really sobering aspect of loudness normalization is that very heavily compressed music ends up sounding dull and feeble compared with more naturally dynamic material.
Spotify has a -11LUFS target, Youtube -13LUFS and iTunes -16LUFS so as you can see, iTunes can actually manage more dynamic range than Spotify, this target should be regulated so all the online stores and streaming services use the same and I believe it will happen in the next few years so… is the loudness war over?
There’s no doubt that large parts of the music industry are embracing loudness normalization, and although it will take time to become the standard way of working everywhere, it looks certain that this change will become universal. In a loudness-normalized environment the current style of peak-normalized material doesn’t fare well at all: the perceived loudness benefit is lost, and the sonically and musically destructive consequences of hyper-compression are clearly exposed.
Instead, loudness normalization positively encourages the use of dynamics and transients. Tracks are made punchy by being dynamic rather than just loud, and compression and limiting become musical effects rather than essential competitive processing. Headroom is restored, inter-sample clipping is banished, and the digital environment finally achieves the sonic quality and dynamic range of which it is capable.
Now is time to make great sounding and dynamic tracks and let the music do the talking!
Glossary: Loudness Terminology
Programme: An individual audio programme, advert, music track, and so on.
Sample Peak: The typical digital sample-peak meter system which indicates the highest amplitude value represented within a batch of digital audio samples. It is typically lower than the True Peak value of the reconstructed analogue waveform, because it ignores any inter-sample peaks.
TP, or True Peak: The maximum peak value of the reconstructed audio waveform (which includes any inter-sample peaks).
dBTP: True peak level in decibels, with reference to digital full scale. The maximum value of the reconstructed audio signal waveform, recognizing any inter-sample peaks.
Target Loudness Level: The intended loudness-normalization level.
Loudness Normalization: A working practice in which an arbitrary loudness level defines the reference point, and the loudness of individual signals is assessed so that they can then be adjusted to match loudness on replay. This approach imposes a headroom margin and thus encourages dynamic variations.
Peak Normalization: A practice whereby the highest peaks of different programmes are aligned to a defined reference level, which encourages engineers to use dynamic range compression to increase perceived loudness.
Programme Loudness: The Integrated Loudness over the duration of the programme item, in LUFS. Also shown as the ‘I’ value on loudness meters.
LU: Loudness Units. A relative loudness value from the Target Loudness level.
LUFS: Loudness Units with reference to digital full scale. The EBU preferred term for the absolute loudness value.
LRA: Loudness Range. The distribution of loudness within a programme (an indicator of the programme’s perceived dynamic range).
Crest Factor: A measure of a signal waveform amplitude, indicating the ratio of the peak to average value.