Loudness / Perceived Loudness / Program Loudness

lufs loudness normalization dynamic range true peak

The subjective perception of audio volume as experienced by the human ear – measured using standardized algorithms (LUFS/LKFS) that approximate human hearing, distinct from simple peak or RMS measurements, and essential for broadcast compliance and consistent listening experiences.

What is Loudness?

Loudness is the subjective perception of audio volume by the human ear. It differs from technical level measurements because it accounts for how humans actually perceive sound.

Basic Principles

Aspect	Description
Definition	Perceived loudness
Measurement	LUFS/LKFS
Basis	Psychoacoustics
Difference from	Peak, RMS

Loudness vs. Peak

Aspect	Loudness	Peak
Measures	Perception	Maximum value
Timeframe	Integrated	Instantaneous
Frequency Weighting	Yes (K-Weighting)	No
Relevance	Listening experience	Clipping

Psychoacoustic Fundamentals

Phenomenon	Description
Fletcher-Munson	Frequency-dependent perception
Temporal Integration	Short-term vs. Long-term
Masking	Loud sounds cover quiet tones
Dynamics	Perception of contrasts

Measurement Algorithms

Standard	Description
ITU-R BS.1770	International standard
K-Weighting	Frequency curve
Gating	Excluding silence
True Peak	Inter-sample peaks

K-Weighting

Frequency Range	Influence
Deep Bass (<100Hz)	Reduced
Bass (100-500Hz)	Slightly reduced
Mids (500-4kHz)	Neutral
Highs (>4kHz)	Slightly boosted

Measurement Types

Type	Time Window	Application
Momentary (M)	400ms	Current loudness
Short-term (S)	3s	Short passages
Integrated (I)	Overall	Program loudness

Loudness Units

Unit	Description
LUFS	Loudness Units Full Scale
LKFS	Loudness K-weighted Full Scale
LU	Loudness Unit (relative)
dBTP	True Peak

Target Values

Application	Target Loudness
Broadcast TV	-24 LKFS
Streaming	-14 LUFS
Cinema	Dialogue-based
Podcast	-16 to -19 LUFS

Loudness Range (LRA)

Range	Description	Example
<5 LU	Very compressed	Pop mastering
5-10 LU	Moderate	Rock, Pop
10-20 LU	Dynamic	Film
>20 LU	Very dynamic	Classical

Measurement Tools

Tool	Type
WLM Plus	Plugin
Youlean Loudness Meter	Free Plugin
Nugen VisLM	Professional
iZotope Insight	Suite

Gating

Type	Threshold	Function
Absolute Gate	-70 LUFS	Ignore silence
Relative Gate	-10 LU	Quiet passages
Combination	Both	Standard ITU

Practical Application

Step	Description
1	Create mix
2	Measure loudness
3	Adjust gain
4	Check True Peak

Loudness War

Aspect	Description
Problem	Mastering louder and louder
Consequence	Loss of dynamics
Solution	Normalization standards
Today	Standards end the war

Streaming Normalization

Platform	Method
Spotify	-14 LUFS Target
YouTube	-14 LUFS Target
Apple Music	-16 LUFS
Tidal	Variable

Cinema Context

Aspect	Description
Reference	85 dB SPL
Dialogue	-31 LKFS
Dynamics	High range
Measurement	Dialogue-based

Dialogue Loudness

Parameter	Description
Anchor	Dialogue as reference
Intelligibility	Clarity
Balance	With music/SFX
Consistency	Across scenes

Common Mistakes

Mistake	Solution
Too loud	Will be normalized down
Too quiet	Wasted headroom
Inconsistent	Automatic adjustment difficult
True Peak Over	Use a limiter

Best Practices

Practice	Reason
Measure early	Identify problems
Know the target value	Platform-specific
Preserve dynamics	Musicality
Consider True Peak	Codec headroom

Today

Loudness management has become standard in professional audio production. With the introduction of EBU R128 and ATSC A/85, there are clear guidelines that improve the viewer experience. Streaming platforms normalize automatically, meaning overly compressed, loud mixes no longer have a competitive advantage – good sound wins over pure level.

From the crafts

Perspectives

Cinematographer

Loudness ist ein Audio-Thema, aber ich verstehe, dass es nicht um reine Pegel geht, sondern wie Menschen Lautstärke wahrnehmen.

Director

Lautheit ist, wie mein Publikum den Ton erlebt. Ein gut gemixtes Projekt hat konsistente Lautheit, sodass Dialog, Musik und Effekte ausbalanciert sind.