2006 April, Volume 54 Number 4

CONTENTS

PAPERS

A Hybrid Technique for Validating Unidimensionality of Perceived Variation in a Spatial Auditory Stimulus Set
Tobias Neher, Tim Brookes, and Francis Rumsey   259
Having a set of audio stimuli that varies along a specified single perceptual dimension, regardless of variations in physical acoustic parameters, would be extremely useful in subjective experiments that require training or reference stimuli. After considering various paradigms for validating such a set, a hybrid technique comprising multidimensional scaling and subject-specific verbalizations proved to be the most promising. This technique was developed further and experiments demonstrated that it revealed which groups of stimuli vary as intended along a single perceptual dimension and which vary along multiple dimensions.

Spatially Modulated Auditory Alerts for Aviation
Durand R. Begault, Mark R. Anderson, and Bryan U. McClain   276
Detection of a nonspeech auditory alert (alarm) in a noisy environment increases when such an alert is moved along a virtual spatial trajectory using a 3-D auditory display. This approach decreases thresholds by as much as 8 dB because of dynamic changes in level and interaural cross-correlation of the signals at the two ears.

ENGINEERING REPORTS

Dynamic Crosstalk Cancellation for Binaural Synthesis in Virtual Reality Environments
Tobias Lentz   283
In order to create a 360-degree virtual reality with free listener movement, a system was designed with a combination of dynamic head-tracking crosstalk cancellation and binaural synthesis of spatial environments. Rather than use two loudspeakers with limited rotational range, the proposed system uses two pairs of loudspeakers with dynamic crossfading as the listener rotates his head through eight sectors. Preliminary tests in an environment with reflections demonstrate the feasibility of the approach.

Model Optimization of Distributed-Mode Loudspeaker Using Attached Masses
Suzhen Zhang, Yong Shen, Xiaoxiang Shen, and Jinglei Zhou   295
While distributed-mode loudspeakers have many advantages compared with conventional cone topology, they usually have excessive fluctuation in frequency response. By attaching area masses, resonances in selective frequency regions can be distributed more evenly, and the excessive fluctuation is reduced. A generic algorithm has been developed to optimize the position, weight, and number of such masses. Simulated results using FEMLAB were experimentally tested in an anechoic chamber, thus validating the approach to improving distributed-mode topologies.

STANDARDS AND INFORMATION DOCUMENTS

AES Standards Committee News   306
Unique identifiers in AES3; audio in ATM networks; audio metadata; forensic audio

FEATURES

28th Conference Preview, Piteå, Sweden   308
    Calendar   311
    Program   312
Audio Power Amplification   319
30th Conference, Saariselkä, Finland, Call for Papers   336

DEPARTMENTS

News of the Sections   324
Upcoming Meetings   328
Sound Track   329
New Products and Developments   331
Available Literature   332
Membership Information   334
Advertiser Internet Directory   335
Sections Contacts Directory   337
AES Conventions and Conferences   344

FPO For the cover:

2006 April, Volume 54 Number 4

spine: 2006 April, Volume 54 Number 4