Internet Audio and Audio Networking

2:00 pm

E-1 Creating Metadata from Audio File Analysis and Its Internet Applications (poster)

Sigmund Joseph Rothschild, University of Colorado-Denver, Denver, CO, USA

Psychoacoustic and perceptual analysis methods can be used to determine the specific content of an audio file and to create data about that file from this analysis. Data that is used to describe data is known as metadata. This may include the identification of a particular audio recording for copyright and Digital Rights Management purposes. This paper examines the underlying technologies, the analysis methods employed, and the application of these methods on the Internet.

No Convention Paper Printed

2:00 pm

E-2 A/V Synchronization Using Modified Packetized Elementary Stream (PES) Over Synchronous Audio Interface (poster)

Miroslav Dokic, Sanjay Joshi, Vladimir Mesarovic and Raghunath Rao, Cirrus Logic Inc., Austin, TX, USA

In the recent years we have witnessed the explosion of digital multimedia technologies and content in both video and audio arenas. The development of digital audio technologies was even more dramatic and versatile than any other form of multimedia. The proliferation of the new audio technologies had a profound impact on content providers, chip manufacturers, product manufactures as well as end consumers. Besides affecting the component-integration, this audio format proliferation also increased the complexity of multimedia systems that support multiple audio formats. One of the major technical challenges in these systems is how to enable these new features in the existing systems with the minimal cost and time-to-market penalties. Typically, the solution is to add a separate external audio decoder, but then the problem is how to achieve the glueless interface between the existing system and the new decoder. This paper addresses the problem of interfacing the external audio decoders with the rest of the multimedia system on the software protocol level.

Convention Paper 5427

2:00 pm

E-3 ACN-A Protocol Suite for Entertainment Technology Networking (poster)

Philip Nye, Engineering Arts, Bournemouth, UK

Over the last five years the trade organization Entertainment Technology and Services Association has been working on ACN - a modern network protocol suite optimized for control of large numbers of diverse pieces of equipment in live performance and other challenging environments where speed and ease of configuration and rapid and reliable response is essential. Input has come from major players right across the entertainment technology industries with contribution of substantial resources from several major companies in the field.

Convention Paper 5429

Mobile Audio

2:00 pm

E-4 Active Control System for Low-Frequency Road Noise Combined with an Audio System (poster)

Hiroyuki Hashimoto, Isao Kakuhari, and Kenichi Terai, Matsushita Electric Industrial Co., Ltd., Kadoma, Osaka, Japan; Yoshio Nakamura, Matsushita Electronic Components Co., Ltd., Kadoma, Osaka, Japan; and Hisashi Sano, Honda R&D Co., Ltd., Haga, Tochigi, Japan (Poster)

We have developed the active control system for low frequency road noise in automobiles combined with an audio system. It is the first commercial application in the world. This system adopts feedback control in the front seats and feedforward control in the rear seat, furthermore a music compensation circuit is applied. So it reduces only the noise in the front seats about 10 dB without canceling out the music. As the result, it is comfortable to the passengers to listen to the music.

Convention Paper 5430

2:00 pm

E-5 Improving the Intelligibility of Aircraft PA Systems (poster)

Peter Mapp, Peter Mapp Associates, Colchester, Essex, UK

A survey carried out by the authors on a range of commercial jet aircraft while in normal flight found a wide variation in perceived intelligibility and operation signal-to-noise ratios of their on-board PA systems. Typical passenger cabin background noise levels of 80-85 dBA (100-105 dBC) were recorded, while many systems were found to operate with either zero or negative S/N ratios. The results of extensive mock-up testing are reported. It is shown that high-frequency dispersion is a major factor contributing to the perceived intelligibility. The use of distributed mode loudspeaker technology was found to bring about significant improvements in clarity and intelligibility, but the effectiveness of RASTI as an accurate intelligibility descriptor under these conditions is questioned.

Convention Paper 5431

Loudspeakers

2:00 pm

E-6 Analysis of Directivity Anomalies in Mid- and High-Frequency Horn Loudspeakers (poster)

Mario Di Cola, Davide Doldi and Davide Saronni, Laboratorio Musica, Novi di Modena, Italy

The directional properties of horn devices are governed by the wavefront's shape presented at the mouth. An analysis of the sound pressure distribution across the horn's mouth that could certainly be helpful to understand how the wavefront is shaped there. Moreover, this could help to understand what happen in some particular circumstances. Midrange beaming or high frequency mouth diffraction phenomena for example, are two well-known obstacles to overcome designing a broadband constant directivity horn. The method forwarded by us in the previous work is here extended to some different cases and improved in the data processing. The results that come out of such analysis will be shown through graphic illustrations. Presented will be the results obtained performing measurements upon real devices correlated to traditional directivity plots as well.

Convention Paper 5432

2:00 pm

E-7 Room Acoustics Modeling of Wavefront Sculpture Technology-Based Systems (poster)

Stéphane Gramondo, Christophe Pignon, and Paul D. Bauman, L-Acoustics, Gometz La Ville, France

The DLL Directivity Interface (DDI) that is available for several industry-standard room acoustics modeling programs allows loudspeaker manufacturers to model line source array performance through either proprietary theoretical formulation, in-house modeling or measurements. Essentially, the DDI provides an interface protocol for entering details of the array configuration which is then used by the proprietary DLL program for calculation of directivity data with arbitrary frequency and angular resolution for the room acoustics modeling program. Use of this new modeling technique is presented for both flat and variable curvature line source arrays. Comparison between measurements and calculations shows that this technique is able to accurately simulate the directivity of line source arrays whereas standard 3D polar balloon modeling techniques are insufficient.

No Convention Paper Printed