AES London 2010
Poster Session P19

P19 - Psychoacoustics and Listening Tests

Monday, May 24, 14:00 — 15:30 (Room C4-Foyer)
P19-1 Auditory Perception of Dynamic Range in the Nonlinear System—Andrew J. R. Simpson, Simpson Microphones - West Midlands, UK
This paper is concerned with the perception of dynamic range in the nonlinear system. The work is differentiated from the generic investigation of “sound quality,” which is usually associated with studies of nonlinear distortion. The proposed hypothesis suggests that distortion products generated within the compressive type nonlinear system are able to act as loudness compensator for the associated amplitude compression in the perceived loudness function. The hypothesis is tested using the Time-Varying Loudness model of Glasberg and Moore (2002) and further tested using AB scale hidden reference type listening test methods. The Loudness Overflow Effect (LOE) is introduced and bandwidth is shown to be a significant limiting factor. Results and immediate implications are briefly discussed.
Convention Paper 8103 (Purchase now)

P19-2 A Subjective Evaluation of the Minimum Audible Channel Separation in Binaural Reproduction Systems through Loudspeakers—Yesenia Lacouture Parodi, Per Rubak, Aalborg University - Aalborg, Denmark
To evaluate the performance of crosstalk cancellation systems the channel separation is usually used as a parameter. However, no systematic evaluation of the minimum audible channel separation has been found in the literature known by the authors. This paper describes a set of subjective experiments carried out to evaluate the minimum channel separation needed such the binaural signals with crosstalk are perceived to be equal to the binaural signals reproduced without crosstalk. A three alternative-forced-choice discrimination experiment, with a simple adaptive algorithm with weighed up-down method was used. The minimum audible channel separation was evaluated for the listeners placed at symmetric and asymmetric positions with respect to the loudspeakers. Eight different stimuli placed at two different locations were evaluated. Span angles of 12 and 60 degrees were also simulated. Results indicate that in order to avoid lateralization the channel separation should be below –15 dB for most of the stimuli and around –20 dB for broad-band noise.
Convention Paper 8104 (Purchase now)

P19-3 Evaluation of Speech Intelligibility in Digital Hearing Aids—Lorena Álvarez, Leticia Vaquero, Enrique Alexandre, Lucas Cuadra, Roberto Gil-Pita, University of Alcalá - Alcalá de Henares – Madrid, Spain
This paper explores the feasibility of using the Speech Intelligibility Index (SII) to evaluate the performance of a digital hearing aid. This standardized measure returns a number, between zero and unity, which can be interpreted as the proportion of the total speech information available to the listener, and correlates with the intelligibility of the speech signal. The paper will focus on the use of the SII as a metric from which to compare the performance of two different hearing aids, in terms of speech intelligibility. From the purpose of this work, experiments employing data from four real subjects with mild-to-profound hearing losses, when using these different hearing aids, will be done. Results will show how the use of the SII can lead to a better selection of a hearing aid in the detriment of others, while avoiding the need for making extensive subjective listening tests.
Convention Paper 8105 (Purchase now)

P19-4 Method to Improve Speech Intelligibility in Different Noise Conditions—Rogerio G. Alves, Kuan-Chieh Yen, Michael C. Vartanian, Sameer A. Gadre, CSR - Cambridge Silicon Radio - Auburn Hills, MI, USA
Mobile communication applications have to address various environmental noise situations. In order to improve the quality of voice communication, not only an effective noise reduction algorithm for the far-end user is wanted, but also an algorithm that helps improve intelligibility for the near-end user in different environmental noise situations is desired. Due to it, the goal of this paper is to improve the overall voice communication experience of mobile device users by introducing a method to improve intelligibility by increasing perceptual loudness of the received speech signal in accordance with the environmental noise. Please note that, due to the characteristics of the mobile devices application, a method capable of working in real time with low computational complexity is highly desired.
Convention Paper 8106 (Purchase now)

P19-5 Contemporary Theories of Tinnitus Generation, Diagnosis, and Management Practices—Stamatia Staikoudi, Queen Margaret University - Edinburgh, Scotland, UK
Tinnitus can be defined as the perception of a sound in the head or the ears, in the absence of external acoustic stimulation. It is a symptom experienced by more than seven million people across the UK and many more worldwide, including children. Its pitch may vary from individual to individual, and it can be described as ringing, whistling, humming, or buzzing amongst other. We will be looking at contemporary theories for its generation, current methods of diagnosis, and management practices.
Convention Paper 8107 (Purchase now)

P19-6 Analytical and Perceptual Evaluation of Nonlinear Devices for Virtual Bass System—Nay Oo, Woon-Seng Gan, Nanyang Technological University - Singapore
Nonlinear devices (NLDs) are generally used in virtual bass systems (VBS). The prime objective is to extend the low frequency bandwidth psychoacoustically by generating a series of harmonics in the upper-bass and/or mid-frequency range where loudspeakers can reproduce well. However, these artificially added harmonics introduce intermodulation distortion and may change the timbre of the sound tracks. In this paper nine memoryless NLDs are studied based on objective analysis and subjective listening tests. The objectives of this paper are (1) to quantify the spectral contents of NLDs when fed by single-tone; (2) to find out which type of NLDs is best for psychoacoustics bass enhancement through subjective listening tests and objective GedLee nonlinear distortion metric; and (3) to investigate whether there is any correlation between subjective listening tests results and objective performance scores.
Convention Paper 8108 (Purchase now)