1. WP 4
Loudness Normalisation
Peter Altendorf, IRT

2. Technical Achievements
• Provision of a Loudness Normalisation web
service compliant with ITU and EBU for UC7a
• Provision of Loudness Analysis results to
support ads insertion in UC7b
• Evaluation of Loudness Normalisation on the
web
26-27 March 2012 NoTube 3rd review 2

3. Loudness Normalisation Process
Chain as Web Service
Metadata Web service for implementation
conversion of loudness normalisation
PrestoSpace Webservice
WP2
TVA
Extract Demux Decompr. Synthesis
Synthesis 1 Synthesis
Recompr. Remux *
Analysis
1 2
WP2
CRUD Service
TVA
26-27 March 2012 NoTube 3rd review 3

4. Normalisation Web Service
– Demo Video –
26-27 March 2012 NoTube 3rd review 4

5. Normalisation Web Service
– Demo –
26-27 March 2012 NoTube 3rd review 5

6. Loudness Web Evaluation
26-27 March 2012 NoTube 3rd review 6

7. Web Evaluation - Feedback
• Feedback in the community:
– Almost 100 participants from >20 countries
– >240 views on notube.tv on Dec 1st 2011 (posting of the
preliminary results in the blog)
• Paper “User Evaluation on
Loudness Harmonisation on the
Web“ accepted for presentation
at the AES 132nd Convention in
Budapest, Hungary, 2012 April
26-29.
26-27 March 2012 NoTube 3rd review 7

8. Web Evaluation – Loudness
adaptation (descriptive)
Preferences of Loudness Adaptations
-7 LU (-30 LUFS) 0 LU (-23 LUFS) +4 LU (-19 LUFS)
100
90
80
70
60
% (N=94)
50
40
30
20
10
0
26-27 March 2012 NoTube 3rd review 8

9. Web Evaluation – Loudness
adaptation (analysis)
-7 LU (-30 LUFS) 0 LU (-23 LUFS) +4 LU (-19 LUFS)
100
90
80
70
60
50
40
30
20
10
0
26-27 March 2012 NoTube 3rd review 9

10. Web Evaluation – Loudness range
adaptation (descriptive)
Preferences of Loudness Range Adaptations
0 dB compression +15 dB compression +25 dB compression
100
90
80
70
60
% (N=94)
50
40
30
20
10
0
Knight and Day Offenbach Beethoven_Lang Lang Shostakovich BMW M5
26-27 March 2012 NoTube 3rd review 10

11. Web Evaluation – Loudness range
adaptation (analysis)
0 dB compression +15 dB compression +25 dB compression
100
90
80
70
60
50
40
30
20
10
0
26-27 March 2012 NoTube 3rd review 11

12. Evaluation Summary
• Loudness adaptation:
– Homogeneous results for all listening parameters under test
– Independence from the listening parameters (“age”, “speaker
type” and “listening level”)
– A strong background noise seems to increase the need for
higher loudness levels
 Verification of the sufficiently accurate approximation of
the human loudness perception for broadcast audio signals
by the algorithm defined in EBU R128 and ITU-R BS.1770-2.
• Loudness range adaptation:
– Results not as homogeneously
– Tendency: Participants seem to prefer rather medium or even
strong loudness range compression to uncompressed audio with
high loudness range.
26-27 March 2012 NoTube 3rd review 12

13. Conclusion
• Proof of concept for loudness normalisation
using dedicated metadata
• Generic approach for loudness normalisation
on the web is challenging and could not be
achieved in the project
• Evaluation shows applicability of ITU-R
BS.1770 and EBU R-128 for web applications
• Loudness Range for internet should not
exceed 20LU (subject to further research)
26-27 March 2012 NoTube 3rd review 13