Saturday, August 12, 2006

Digital Broadcasters|AES Seoul Papers (7)

The 29th AES Conference, "Audio for Mobile and Handheld Devices", all digital, September 2 to 4, 2006 Seoul National, lUniversity Campus

Digital Audio Presentations - Part 7

In Digital Audio - Using aacPlus for Premium Color Ring Back Tones

Invited Speakers:

Andreas Ehret, Michael Schug and Holger Hoerich, Coding Technologies, Germany

Seongsoo Park, Dae Sic Woo and Dong-Hahk Lee, SK Telecom, Korea

Jin Soo Park and Sung Il Park, Mcubeworks, Korea

aacPlus is a highly efficient digital audio coding scheme which is capable of providing very good audio quality at low bit rates. Color ring back tone services provide a music experience while waiting for a called person to answer the phone, replacing the traditional beep sound ring tones. These services have been commercialized since 2002 but some audio quality issues remain as the existing speech codecs are being used to code music. With the increasing availability of aacPlus on mobile phones it becomes possible to use aacPlus for this kind of application and it will be the core component of new premium color ring back tone services. The new digital service will provide significantly improved audio quality which allows for an excellent user experience with music ring back tones. The basic parameters and extensions to adapt the digital aacPlus codec to the transmission channel are described. Simulation and subjective listening test results are also presented in this paper.

Low Complexity Virtual Bass Enhancement Algorithm for Portable Digital Multimedia Devices

Invited Speakers:

Manish Arora, HyuckJae Lee, Seongcheol Jang, Samsung Electronics, Korea

Earbuds and Insert Ear Earphones have gained immense popularity with digital mobile multimedia systems recently owing to their convenience and easy low cost design. Unfortunately their design is subject to severe constraints especially affecting their low frequency signal performance. Bass signal performance contributes significantly to the user perceived sound quality and a good bass signal reproduction is essential. Increasing the sound energy in the bass signal range is an unviable solution since the gain required are exceedingly high and signal distortion occurs because of speaker overload. Recently methods are being proposed to invoke low frequency illusion using psychoacoustic phenomena of the missing fundamental. This paper proposes a simple and effective digital signal processing method to create bass signal illusion using the missing fundamental effect, at a complexity of 12 MIPS on Motorola 56371 audio DSP.

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