AES Journal

Journal of the AES

2002 September - Volume 50 Number 9


Spatial Quality Evaluation for Reproduced Sound: Terminology, Meaning, and a Scene-Based Paradigm (PDF-202K)  
Francis Rumsey    651
Improving the quality of spatial reproduction suffers because of an incomplete definition of the subjective attributes that contribute to the experience of space. Moreover, the lexicon of spatial concepts is often ambiguous and ill defined. This review of existing standards and research highlights the problem of extending controlled laboratory results to real applications of sound reproduction, especially when different goals, such as evaluating equipment versus modeling human perception, are involved.  

  Be the first to discuss this paper

Describing Telephone Speech Codec Quality Degradations by Means of Impairment Factors (PDF-189K)  
Sebastian Möller and Jens Berger    667
Predicting the quality of a telephone channel with multiple sources of degradations from a variety of codecs is a labor-intensive activity that must be repeated for each condition. The authors propose a perceptually based model that produces a single equipment impairment index as a way to approximate the degradation contributed by a particular device. Preliminary results suggest that the proposed algorithm, based on auditory tests, provides insight into the expected results.  

  Be the first to discuss this paper

Low-Crest-Factor Multitone Test Signals for Audio Testing (PDF-276K)  
Alexander Potchinkov    681
Test signals composed of a large number of discrete frequencies offer the advantage of high-speed measurements and the ability to simulate the spectrum of natural audio under controlled conditions. However, selecting the phase relationship to minimize the crest factor becomes a special problem. Minimizing the crest factor increases the signal power for a fixed clipping level. This paper shows that ad hoc schemes are useful but often inferior to a formal optimization, and that they should not be used if enough compute time is available for a theoretical optimization.  

  Be the first to discuss this paper

About the 10-dB Switch of a Condenser Microphone in Audio Frequency Circuits (PDF-143K)  
Holger Pastillé and Martin Ochmann    695
Because high sound levels can overload the input preamplifier of a condenser microphone, one of two techniques is typically used to reduce the level: switching a parallel capacitor across the microphone or reducing the polarizing voltage. Both techniques reduce the signal level but with very different effects on nonlinearity. This paper explores both the mathematical and practical implications of level reduction, with a warning to users faced with an overload condition.  

  Be the first to discuss this report

AES Standards Committee News (PDF-29K)    703
Internet communications update; synchronization; forensic audio; microphone measurement; listening tests; audio connections Survey: Fiber Optic Connectors (PDF-12K)    insert
21st Conference Report, St. Petersburg (PDF-1.0MB)    710
23rd Conference, Copenhagen, Call for Papers (PDF-19K)    737
24th Conference, Banff, Call for Contributions (PDF-21K)    738
Review of Acoustical Patents (PDF-152K)    708
News of the Sections (PDF-117K)    718
Sound Track (PDF-18K)    725
Upcoming Meetings (PDF-23K)    726
New Products and Developments (PDF-236K)    727
Available Literature (PDF-13K)    731
Membership Information (PDF-681K)    732
Advertiser Internet Directory (PDF-25K)    734
In Memoriam (PDF-22K)    736
AES Special Publications (PDF-87K)    741
Sections Contacts Directory (PDF-37K)    746
AES Conventions and Conferences (PDF-49K)    752
Cover & Sustaining Members List (PDF-32K)    
VIP List & Editorial Staff (PDF-28K)    
Ads In This Issue (HTML)    
Download Entire Journal As One PDF (PDF-3.4MB)    
AES - Audio Engineering Society