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The Loudness Wars and ITU-R BS.1770
T h o m a s L u n dT C E l e c t r o n i c A / S
D e n m a r k
K B S • S e o u l • J u n e 1 7 , 2 0 1 5
Befo
re B
S.17
70
P e a k L e v e l M e t e r i n g
Bad for Broadcast Bad for Music
Befo
re B
S.17
70
LoudnessModels
Leq(K) is simple and performs well
BS.1770 Loudness
Left Pre Filter MeanSquareRLB Filter
�
Right
Center
L Srnd
R Srnd
LFE Currently not used in Loudness Calculations
0.0 dB
Pre Filter RLB Filter 0.0 dB
Pre Filter RLB Filter 0.0 dB
Pre Filter RLB Filter +1.5 dB
Pre Filter RLB Filter +1.5 dB
MeanSquare
MeanSquare
MeanSquare
MeanSquare
Power Gain Sum
Works for mono, stereo and 5.1
Words: LUFS, LKFS and LU
LUFS = LKFS
Unit for relative loudness levelCompare with [dB] for peak levelLoudness at Target Level = 0 LU
LU
Unit for absolute loudness levelCompare with [dBFS] for peak level-23.0 LUFS is the same as -23.0 LKFSOnly the spelling is different
LUFS and LU0 LU denotes Target Level
In this exampleTarget Level is -23 LUFS
Remember: LUFS is the same as LKFS
Meter Example: LUFS and LUTarget at -23 LUFS
Program Loudness
Use to normalize programsto a Target Level -24
-30
-36
-42
-48
-54
-60
0
-4
-8
-12
-16
-20
LUFS
Ingest Corrected
Target: -23 LUFS
Measure: -28 LUFS
Program Loudness
Use to normalize programsto a Target Level -24
-30
-36
-42
-48
-54
-60
0
-4
-8
-12
-16
-20
LUFS
Ingest Corrected
A simple gain offsetbrings the program on Target
Loudness on three time-scales
Program Loudness
MomentaryLoudness
Short-termLoudness
Start End
400 ms
3 s
1
2
Analog Level:Black Line
Digital (sample) Level:Red Dots
True-peak Level:Grey Lines
AES 23 Nielsen & Lund, 2003True-peak LevelEven in a linear audio system, analog and digital level is not the same
Part of BS.1770 also
Use Loudness meterto set levels
Only use True-peak meterto avoid overload
Peak level of a program or trackrelative to its Loudness, [dB]
Audio Terminology
PLRPeak to Loudness Ratio
LRALoudness RangeTypical Loudness variationinside a program or track, [LU]
Peak handling capability of a systemrelative to Target Level, [dB]
Headroom Dynamic RangeMax/min signal ratio of a system, [dB]Not a relevant term in this context
program or music tracksystem
Audio Terminology
PLR = Height Headroom = Clearance
8
9
10
11
12
13
14
15
16
17
18
63 66 69 72 75 78 81 84 87 90 93 96 99 02 05 08 11
Ortner, 2012Peak to Loudness Ratio 1963 - 2011 Year
PLR [dB] 7.400 most popular music tracksGermany, UK, US
Productions below the dotted line rarely sound good on fine speakers
Audi
o Q
uality
Mark KnopflerBritish Grove, London
Japan Loudness Status: TR-B32All programs: BS.1770-3Target Level: -24 LUFSTrue-Peak Max: -2 dBTP
ITU-R WPC6: Extension of BS.1770 to 22.2
US Loudness Status: ATSC A/85 Commercials: BS.1770-3Programs: Speech levelTarget Level: -24 LUFSTrue-Peak Max: -2 dBTP
Uncertainty when measuring programs...
Definition
Classification
Measurement0
3
6
9
12
15
Loudness Speech
[dB]
Results: Cumulative Uncertainty
+8
6
4
2
0
2
4
6
-8 Program Interstitial Drama Interstitial Film
[LU] ATSC A/85 uncertaintiesDefinitionClassificationMeasurement
1.Count Basie:“Mean Old World”Secret stereo recordingby Bruce Swedien1959
2.Imagine Dragons:
“Demons”From album
Night Visions2012
Each track loudness-normalized to -18 LKFS/LUFS
ReferencesKarl Küpfmüller (1962). Edit by K. Steinbuch, Springer, BerlinNachrichtenverarbeitung im Menschen
Benjamin Libet et al. (1979). PubMed id#427530. Bethesda, MDSubjective Referral of the Timing for a Conscious Sensory Experience
Rudolf Ortner (2012). Donau Universität, KremsJe lauter desto bumm! - The Evolution of Loud
Nielsen & Lund. (1999 - 2006). AES 23, 107, 109, 111, 121Stop Counting Samples and 0 dBFS+ Level
Skovenborg & Lund. (2007 - 2014). AES 123, 125, 127, 132, 135, 137Loudness Descriptors to Characterize Programs and Music Tracks
ATSC A/85, EBU R128, ITU-R BS.1770, TR-B32
AES 58
More Info
End
Prevention of Hearing Loss from the use ofPersonal Music Players
11:00June 30
