how to find future audio formats?

© Fraunhofer IIS

VDT-Symposium, 2009 Hohenkammer

How to Find Future Audio Formats?

Andreas Silzle, Thomas BachmannFraunhofer-Institut für Integrierte Schaltungen IIS

[email protected]

© Fraunhofer IIS

How to Find Future Audio Formats?

1.

General classification of audio reproduction systems

2.

What is important for future audio formats?

3.

Why height sound-reproduction?

4.

Questionnaire for a future audio format

5.

Taxonomy for audio formats

Content

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1.

General Classification of Audio Reproduction Systems

Reproduction systemsPhysically based

Wave-Field Synthesis (<2 kHz for a loudspeaker distance of 17 cm, microphone array, only 2D reproduction) [Berkhout 1988, Fraunhofer IDMT 2009]

Perceptually based

Mono

2 channel Stereo

5.1 Format [Rumsey 2001]

Both categories (dependent on number of loudspeakers)

Ambisonics [Gerzon 1973]

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1.

Transport Format versus Reproduction System

Introduction Transport Format Reproduction

System

~1923 Mono Mono

~1961 2 ch. Stereo 2 ch. Stereo

19935.1 PCM, MPEG Layer II, AAC, Dolby Digital, DTS

5.1 Multichannel [ITU-R BS.775 1994]

2007 MPEG Surround

(32 ch.)Dolby 7.1DTS 7.1TH 10.2NHK 22.2?

2010 MPEG SAOC (Spatial

Audio Object

Coding)

? ?

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2.

What is Important for Future Audio Formats or Systems?

What is present in current systems?

Speaker/instrument recognition (timbre)Room recognition (reverberance)Localization information in StereoEnvelopment in 5.1 (in 2D)

What should be present in future systems?

Localization information in 3DRoom perception in 3D?

What is not subject of this investigation

Meta data [Fraunhofer IDMT 2009b]Interactivity, e.g. [Silzle 2004]Multi-modal systems, e.g. [Altinsoy 2006]Bit resolution, sampling frequencyNHK 22.2 [Hamasaki

2004]

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2.

Current Attempts for Future Audio Systems with Height Information

Ambisonics (Gerzon, 1973) [Ambisonic 2007]

Ambiophonics (Ralph Glasgal, 1995) [Glasgal 1995]

10.2 System (Tomlinson Holman, 2000) [Holman 2000]

2+2+2 System (Dabringhaus, 2001) [Dabringhaus 2009]

22.2 System (NHK, 2004) [Hamasaki 2004]

DTS-HD, 7.1 (DTS, 2006) [DTS 2009]

Dolby Pro Logic IIz, 9.1 (Dolby Laboratories, 2009) [Dolby 2009]

…

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3.

Why Do We Need Height Sound-Reproduction?

Direct sound sources from above(static or slow moving)

Singing bird

God’s channel (speaker from above)

?

Screen related sound sources from different heights

Recording room reflections from above

Height is the last missing dimension in reproduction

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3.

What Do We Like to Achieve with Height Sound- Reproduction?

Same step size of improvement in Overall Quality like Mono – Stereo – 5.1 – n.m

Precise localization of height from the front and abovePlausible auditory width or spaciousness for elevated auditory events

Plausible reverberance (room perception)

?

Constraints

Number of reproduction loudspeaker n between 5 and 22System should work with different numbers of loudspeakers

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4. Questionnaire for a Future Audio Format

1.

For which applications is a new audio format with height reproduction

1.1 Radio

1.2 TV

1.3 Cinema

1.4 Gaming consoles

1.5 Internet

1.6 Car

1.7 …

Scale 0 –

not necessary

1 –

less important

2 –

important

3 –

very important2.

Number of loudspeakers and positions (azimuth and elevation in degree)3.

What else is important?

Thank you very much for participation!

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Qua

Timbre

Adapted

from

[Silzle

2007]

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5. Benefits from the Taxonomy

Necessity to collect the influencing factors

Overview of influencing factors

Structure of the whole problem

Multivariate optimization problem

Possibility to quantify the problem

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6. Summary

General classification: Physically and perceptually based reproduction system

What is important: Last missing dimension – height

Questionnaire for a future audio format

Taxonomy for audio formats to get an overview

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7. Literature

[Berkhout

1988] Berkhout, A. J. (1988). "A Holographic

Approach to Acoustic

Control." J. Audio Eng. Soc. 36(12): 977-995.[Fraunhofer IDMT 2009] http://www.idmt.fraunhofer.de/de/presse_medien/download/produktinformation/09_wfs_de.pdf[Rumsey

2001] Rumsey, F. (2001). Spatial

Audio. Oxford, Focal

Press.[Gerzon

1973] Gerzon, M. A. (1973). "Perophony: With-Height

Sound Reproduction." J. Audio Eng. Soc. 21(1): 3-10.[ITU-R BS.775 1994] ITU-R Recommendation-BS.775-1 (1994). Multichannel

stereophonic

sound

system

with

and without

accompanying

picture. Geneva, Suisse, Intern. Telecom Union.[Fraunhofer IDMT 2009b] http://www.idmt.fraunhofer.de/eng/business%20areas/ba_metadata.htm[Silzle

2004] Silzle, A., P. Novo, et al. (2004). IKA-SIM: A system

to generate

auditory

virtual

environments. 116th AES Convention, Berlin, Germany.

[Altinsoy

2006] Altinsoy, M. E. (2006). Auditory-Tactile

Interaction in Virtual

Environments. (Doctoral

dissertation). Institut für Kommunikationsakustik, Ruhr-Universität Bochum.

[Hamasaki

2004] Kimio

Hamasaki, S. K., Hiroyuki

Okubo, Koichiro

Hiyama, and Wataru

Hatano

(2004). 5.1 and 22.2 Multichannel

Sound Productions

Using

an Integrated

Surround

Sound Panning

System. 117th AES Convention, San Francisco, USA.

[Ambisonic

2007] http://www.ambisonic.net/[Holman

2000] Holman, T. (2000). 5.1 Surround

Sound Up and Running, Focal

Press.[Glasgal

1995] Glasgal, R. and K. Yates (1995). Ambiophonics

-

Beyond

Surround

Sound to Virtual

Sonic

Reality, Ambiophonics

Institute.

[Darbringhaus 2009] http://www.mdg.de/frame2.htm[DTS 2009] http://de.wikipedia.org/wiki/Digital_Theater_Systems_High_Definition[Dolby 2009] http://www.dolby.com/consumer/technology/prologic-IIz.html[Silzle

2007] Silzle, A. (2007). Generation of quality

taxonomies

for

auditory

virtual

environments

by

means

of systematic

expert

surveys. (Doctoral

dissertation). Institut für Kommunikationsakustik, Ruhr-Universität Bochum.[Silzle

2009] Silzle, A., S. Geyersberger, et al. (2009). Vision and Technique

behind

the

New Studios and Listening

Rooms

of the

Fraunhofer IIS Audio Laboratory. 126th AES Convention, Munich, Germany.

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