AES San Francisco 2008
Paper Session P22
Sunday, October 5, 9:00 am — 11:30 am
: Alan Seefeldt
, Dolby Laboratories - San Francisco, CA, USAP22-1 Assessing the Acoustic Performance and Potential Intelligibility of Assistive Audio Systems for the Hard of Hearing and Other Users
, Peter Mapp Associates - Colchester, Essex, UK
Around 14% of the general population suffer from a noticeable degree of hearing loss and would benefit from some form of hearing assistance or deaf aid. Recent DDA legislation and requirements mean that many more hearing assistive systems are being installed—yet there is evidence to suggest that many of these systems fail to perform adequately and provide the benefit expected. There has also been a proliferation of classroom and lecture room “soundfield” systems, with much conflicting evidence as to their apparent effectiveness. This paper reports on the results of some trial acoustic performance testing of such systems. In particular the effects of system microphone type, distance, and location are shown to have a significant effect on the resultant performance. The potential of using the Sound Transmission Index (STI) and in particular STIPa, for carrying out installation surveys has been investigated and a number of practical problems are highlighted. The requirements for a suitable acoustic test source to mimic a human talker are discussed as is the need to the need to adequately assess the effects of both reverberation and noise. The findings discussed in the paper are also relevant to the installation and testing of boardroom and conference room telecommunication systems.
Convention Paper 7626 (Purchase now)P22-2 Aging and Sound Perception: Desirable Characteristics of Entertainment Audio for the Elderly
, Dolby Laboratories - San Francisco, CA, USA
During the last few years the research community has made substantial progress toward understanding how aging affects the way the ear and brain process sound. A review of the literature supports our experience as audio professionals that elderly listeners have preferences for the reproduction of entertainment audio that differ from those of young listeners. This presentation reviews the literature on aging and sound perception with a focus on speech. The review identifies desirable audio reproduction characteristics and discusses signal processing techniques to generate audio that is suited for elderly listeners.
Convention Paper 7627 (Purchase now)P22-3 Speech Enhancement of Movie Sound
—Christian Uhle, Oliver Hellmuth, Jan Weigel
, Fraunhofer Institute for Integrated Circuits IIS - Erlangen, Germany
Today, many people have problems understanding the speech content of a movie, e.g., due to hearing impairments. This paper describes a method for improving speech intelligibility of movie sound. Speech is detected by means of a pattern recognition method; the audio signal is then attenuated during periods where speech is absent. The speech signals are further processed by a spectral weighting method aiming at the suppression of the background noise. The spectral weights are computed by means of feature extraction and a neural network regression method. The output signal finally carries all relevant speech with reduced background noise allowing the listener to follow the plot of the movie more easily. Results of numerical evaluations and of listening tests are presented.
Convention Paper 7628 (Purchase now)P22-4 An Investigation of Audio Balance for Elderly Listeners Using Loudness as the Main Parameter
—Tomoyasu Komori, Toru Takagi
, NHK Science and Technical Research Laboratories - Tokyo, Japan; Kohichi Kurozumi
, NHK Engineering Service, Inc. - Tokyo, Japan; Kazuhiro Murakawa
, Yamaki Electric Corporation - Tokyo, Japan
We have been studying the best sound balance for audibility for elderly listeners. We conducted subjective tests on the balance between narration and background sound using professional sound mixing engineers. The comparative loudness of narration to background sound was used to calculate appropriate respective levels for use in documentary programs. Monosyllabic intelligibility tests were then conducted in a noisy environment with both elderly and young people and a condition that complicates hearing for the elderly was identified. Assuming that the recruitment phenomenon and reduced ability to separate narration from background sound cause hearing problems for the elderly, we estimated appropriate loudness levels for them. We also constructed a prototype to assess the best audio balance for the elderly objectively.Convention Paper 7629 (Purchase now)P22-5 Estimating the Transfer Function from Air Conduction Recording to One’s Own Hearing
—Sook Young Won, Jonathan Berger
, Stanford University - Stanford, CA, USA
It is well known that there is often a sense of disappointment when an individual hears a recording of his/her own voice. The perceptual disparity between the live and recorded sound of ones own voice can be explained scientifically as the result of the multiple paths via which our body transmits vibrations from the vocal cords to the auditory system during vocalization, as opposed to the single air-conducted path in hearing a playback of one’s own recorded voice. In this paper we aim to investigate the spectral characteristics of one’s own hearing as compared to an air-conducted recording. To accomplish this objective, we designed and conducted a perceptual experiment with a real-time filtering application.
Convention Paper 7630 (Purchase now)