Hugo Fastl's research while affiliated with Technische Universität München and other places

Publications (193)

Chapter
Im Innenohr werden Luftschwingungen in bioelektrische Impulse transformiert. Diese Nervenimpulse werden über verschiedene Stationen der Hörbahn weitergeleitet, wobei eine deutliche Reduktion der Datenmenge (bit/s) stattfindet. Parallel zur Verarbeitung im Hörsystem werden vegetative, hormonelle und emotionalen Funktionseinheiten aktiviert. Die bewu...
Article
Background. After implantation of cochlear implants with hearing preservation for combined electronic acoustic stimulation (EAS), the residual acoustic hearing ability relays fundamental speech frequency information in the low frequency range. With the help of acoustic simulation of EAS hearing perception the impact of frequency and level fine stru...
Article
In this study, an influence of vehicle-exterior image on sound quality evaluation was investigated. Luxury- or sporty-vehicle image was presented to Japanese or German frequent drivers, while listening to an acceleration sound. Subsequently, loudness, luxury and sportiness for the sound were rated. As the result, significant influence was not obser...
Article
The aim of this study is to simulate speech perception with combined electric-acoustic stimulation (EAS), verify the advantage of combined stimulation in normal-hearing (NH) subjects, and then compare it with cochlear implant (CI) and EAS user results from the authors' previous study. Furthermore, an automatic speech recognition (ASR) system was bu...
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The reduced noise of electric and hybrid electric vehicles has been of particular concern because of the potential danger that these vehicles pose to pedestrians when their approach is inaudible against background noise. To address this issue, the use of additional warning sounds in such vehicles is being considered in various countries. The aim of...
Chapter
Im Innenohr werden Luftschwingungen in bioelektrische Impulse transformiert. Diese Nervenimpulse werden über verschiedene Stationen der Hörbahn weitergeleitet, wobei eine deutliche Reduktion der Datenmenge (bit/s) stattfindet. Parallel zur Verarbeitung im Hörsystem werden vegetative, hormonelle und emotionalen Funktionseinheiten aktiviert. Die bewu...
Article
A study was conducted to examine Influences of vehicle-exterior images on loudness ratings of Japanese against German drivers. Character ratings of vehicle-exterior images were carried out to determine the participants' overall impression of the images, and to select the images for the following loudness-rating experiment. Thirty exterior images of...
Conference Paper
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The sound quality of machinery noises is multi-dimensional and is often examined using semantic differential. In this case the overall impression of sound quality is judged. However, sound quality may vary according to the temporal stream of sounds. In this study, sound quality of electric home appliances was judged using the continuous judgment by...
Conference Paper
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Die gezielte Entwicklung des Fahrzeuggesamtgeräuschs ist in der Praxis, aufgrund der Vielzahl an beitragenden Quellen, eine Herausforderung. Durch detailliertes Wissen um die Beiträge der einzelnen Quellen, können Änderungen am Fahrzeug beziehungsweise den beteiligten Schallquellen effizient ermittelt werden. Für die Analyse der Beiträge verschiede...
Article
In this study, influences of vehicle exterior images on sound quality ratings of acceleration sounds were investigated. Luxury and sporty vehicle images were presented to German or Japanese frequent drivers, while listening to acceleration sounds. Subsequently, loudness, luxury, and sportiness of the sounds were rated. The results indicate that the...
Conference Paper
Full-text available
In order to optimize the acoustic package of a vehicle, cost and weight are, besides the acoustical performance, the fundamental objectives. Detailed knowledge about the noise emitting surfaces in the vehicle interior is important for an efficient development process. To analyze contributions from vehicle cabin surfaces to the interior noise, the p...
Conference Paper
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Vehicle development regarding the emitted exterior noise is a challenging task. In addition to stringent legal requirements to reduce noise exposure, also high expectations of the sound quality have to be considered during the development process. In order to manipulate the vehicle exterior noise in a manner more efficient than trial and error, kno...
Conference Paper
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Modern diesel engines meet the demand for high power-engines while strict emission regulations have to be fulfilled. Therefore, diesel engines entered vehicle segments where the expectations on the sound quality are exceptionally high. Sound Quality and fuel efficiency are often conflicting goals during the development of a diesel engine. The typic...
Article
The field of psychoacoustics studies relations between acoustic stimuli, defined in the physical domain, and the hearing sensations elicited by these stimuli. The plenary lecture will address questions of stimulus generation and presentation. Both traditional methods and more recent methods like wave field synthesis will be touched. Concerning hear...
Article
The frequency dependent level correction necessary for a binaural synthesis system to elicit via headphones the reference scene loudness of narrow-band signals is referred to as loudness transfer function. An ideal binaural synthesis system provides frequency independent loudness transfer functions for every listener. The frequency dependence of th...
Article
Modern diesel engines meet the demand for high power-engines while strict emission regulations have to be fulfilled. Therefore, diesel engines entered vehicle segments where the expectations on the sound quality are exceptionally high. Sound quality and fuel efficiency are often conflicting goals during the development of a diesel engine. The typic...
Article
Vehicle development regarding the emitted exterior noise is a challenging task. In addition to stringent legal requirements to reduce noise exposure, also high expectations of the sound quality have to be considered during the development process. In order to manipulate the vehicle exterior noise in a manner more efficient than trial and error, kno...
Article
Objective: The aim of the study was to measure and compare speech perception in users of electric-acoustic stimulation (EAS) supported by a hearing aid in the unimplanted ear and in bilateral cochlear implant (CI) users under different noise and sound field conditions. Gap listening was assessed by comparing performance in unmodulated and modulate...
Conference Paper
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Piezoelectric accelerometers are widely used for vibration measurements, because of their robustness and reliability, which lead to stable transfer characteristics. Typical piezoelectric accelerometers show good linearity over wide frequency and dynamic ranges. While the linear behavior is understood and documented, specifications of the nonlinear...
Conference Paper
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The usage of Low Weight Reinforced Thermoplastics (LWRT) in automotive applications promises to reduce noise immission in the vehicle interior as well as to reduce weight. This reduction of noise is discussed using the example of the air conditioning system. These differences in sound were assessed using algorithmic evaluations as well as subjectiv...
Conference Paper
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In the framework of the research network FORLärm, psy-choacoustic aspects of helicopter sounds are studied. The partner from industry is Eurocopter, and from Technische Universität München, the Institue of Aerodynamics and Fluid Mechanics as well as the AG Technical Acoustic are involved. As a first topic of the cooperation, the noise produced by...
Conference Paper
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Due to the rising demand for high-power engines, although strict emission regulations must be fulfilled, the share of diesel-powered cars is steadily increasing. Since the sound quality of diesel engines has improved over the years, these entered both executive and luxury car segment, where the expectations of sound quality are exceptionally high....
Conference Paper
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For a quantitative ranking of contributions from several sources via different transfer paths to a response, in this example the vehicle interior sound, Transfer Path Analysis is applied. The method used in this experiment is the Operational Transfer Path Analysis, which calculates linearized transfer functions between selected source and response...
Article
A novel system for the reproduction of vir-tual acoustics is presented in theory and prac-tice. The system combines wave field synthe-sis, binaural techniques and transaural au-dio. Stable localisation of virtual sources is achieved for listeners that are allowed to turn around and rotate their heads. Focused sources are used for transaural signal...
Conference Paper
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Bei der Auslegung von Gebläsen sind typischerweise Druckdifferenz und Volumenstrom maßgebliche Faktoren. Die technische Weiterentwicklung wird vor allem durch steigende Anforderungen an Wirkungsgrad, Geräuschpegel und Klangqualität der Gebläse vorangetrieben. Für die Optimierung der Geräusche ist die Berücksichtigung der Wahrnehmung durch den Mensc...
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Background sounds, such as narration, music with prominent staccato passages, and office noise impair verbal short-term memory even when these sounds are irrelevant. This irrelevant sound effect (ISE) is evoked by so-called changing-state sounds that are characterized by a distinct temporal structure with varying successive auditory-perceptive toke...
Article
The free-field response of NordicNeuroLab AudioSystem electrostatic headphones for use in functional magnetic resonance imaging (fMRI) is determined by loudness comparisons with free-field equalized Beyerdynamic DT 48 headphones. Based on these measurements, an active equalizer with resonances at 0.55, 1.5, and 6.9 kHz is developed, realized, and t...
Conference Paper
Typically, the magnitude of a reflective acoustical system's transfer function shows strong variation over frequency. This variation may cause technical problems when the transfer function is employed for auralization purposes, since large linear amplification is required to play back signals convolved with the corresponding impulse response. For t...
Article
Although their basic concept is similar, the current standards for the calculation of loudness, ANSI S3.4-2007 and DIN 45631 (1991), produce significantly different results for many kinds of sounds. While their values for pure tones can be explained by the equal loudness contours of their times, they also show huge discrepancies for broadband sound...
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Full-text available
Electric and hybrid electric vehicles (EV/HEV) have the advantage of being more environmentally friendly and quieter than internal combustion engine vehicles. However, reduced noise can also lead to potentially dangerous situations for pedestrians when an oncoming vehicle is inaudible due to background noise (e.g. Kerber and Fastl, internoise 2007)...
Conference Paper
Binaural synthesis is a sound reproduction technology based on the convolution of sound signals with impulse responses defined between a source and a listener's eardrums. The convolution products are typically presented by headphones. For perceptual verification, subjects traditionally remove the headphones to listen to the corresponding real scena...
Chapter
Acquiring a comprehensive understanding of how people perceive loudness in daily environments requires us to take the study of loudness out of artificial controlled laboratories and observe the perception of loudness under more ecologically valid conditions. In doing so, we find that some assumptions made in the laboratories do not apply to daily e...
Article
As early as 1926 the late Professor Barkhausen from Dresden proposed a procedure for measuring noise, based on features of the human hearing system, which was patented in 1927. He used the psychoacoustic method of loudness comparisons which eventually led to the phon scale. His groundbreaking proposal to use human sound perception for noise measure...
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The loudness of a sound depends, among other parameters, on its temporal shape. Different loudness models were proposed to account for temporal aspects in loudness perception. To investigate different dynamic concepts for modeling loudness, predictions were made with the two current loudness models of Glasberg and Moore [J. Acoust. Soc. Am. 50, 331...
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Binaural room synthesis is a sound reproduction technology that is, for a normal hearing listener, based on convolution of the sound signals to be reproduced with the impulse responses of the sound pressure propagation paths from the sources to be simulated to the listener's eardrums. The convolution products are then presented by adequately equali...
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The psychophysical phenomenon called ventriloquism effect describes a possibly occurring influence of a visual stimulus on the judgment of a sound source's perceived position. The term minimum audible angle usually denotes the just distinguishable horizontal angular deviation between two sound sources. It depends on the direction of the sound sourc...
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Wave field synthesis is an audio reproduction procedure aiming to produce a sound field completely correct at least within the so called listening area. In theory, the exact synthesis is possible under certain circumstances based on the Kirchhoff-Helmholtz integral equation. For practical realizations, usually closed loudspeaker boxes are employed....
Article
In Germany, reference time signals from an atomic clock are distributed via a long-wave radio station called DCF77. As a rule, both radio clocks and wrist watches set their actual time as well as the switching between summer and winter time using the DCF77. Apart from this service which started in the 1970ties, more recently studies are underway ho...
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A new system for single-channel speech enhancement is proposed which achieves a joint suppression of late reverberant speech and background noise with a low signal delay and low computational complexity. It is based on a generalized spectral subtraction ...
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Recent studies have shown that spectral loudness summation depends on duration. Modifications of a current loudness model were investigated with respect to their ability to predict this effect. The original version of the model could not simulate the duration dependence of spectral loudness summation. To reconcile the model with the loudness data,...
Article
  Basic research in psychoacoustics and its applications are discussed. Psychophysical laws should be robust in order to be used for practical purposes. The importance of the development and use of appropriate psychophysical methods in relation to the present study is introduced. When laboratory findings are applied to real-life situations, there a...
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This experiment investigates the effect of images of differently colored sports cars on the loudness of a simultaneously perceived car sound. Still images of a sports car, colored in red, light green, blue, and dark green, were displayed to subjects during a magnitude estimation task. The sound of an accelerating sports car was used as a stimulus....
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Verbal short-term memory capacity is reduced significantly during certain background sounds. Remembering a series of digits is significantly impaired by speech or music with prominent staccato passages whereas, for example, music with prominent legato passages does not disturb performance in comparison to silence. This so-called Irrelevant Sound Ef...
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Databases of head related impulse responses (HRIRs) for binaural synthesis can be measured either in anechoic or reflective environments. If high synthesis quality is needed, miniature microphone measurements are performed in the ear canals of each individual user (individual measurement). Sometimes impulse responses measured in the ear canals of o...
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Previous experiments showed that images of differently colored trains and sports cars can influence the loudness ratings given by subjects via free magnitude estimation. Red vehicles caused subjects to rate the loudness of simultaneously presented train or car sounds higher relative to green vehicles. To investigate whether these loudness differenc...
Article
Sounds of idling Diesel engines were rated according to their Dieselness with two different psychoacoustic methods. On the one hand, a yesno procedure was used. Subjects were presented sounds of two seconds duration and had to answer by yes or no to the following question: Does this sound stem from a Diesel engine? Histograms were calculated and a...
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Wave field synthesis utilizes a large number of loudspeakers to generate a desired wave field. It therefore is necessary to drive each speaker with an independent signal, which requires as many amplifier and soundcard channels as there are loudspeakers. These enormeous hardware costs make research and development very expensive and time consuming....
Article
The term "virtual headphone" refers to specially designed loudspeaker systems aiming for transmission characteristics equal to real headphones. Particularly of interest is the exact pre-filtering of the speaker signals to compensate the effect of head related transfer functions (HRTFs) between loudspeakers and ear canal. These so-called "HRTF inver...
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Psychological evaluations of copy machine noise are in progress to lower acoustical noise and to avoid disturbing the office environment. Psychological experiments were made for Japanese, American and German participants to examine cultural differences in sensitivity to copy machine noise using the Semantic Differential. Seventeen copy machine and...
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Selected subjects with bilateral cochlear implants (CIs) showed excellent horizontal localization of wide-band sounds in previous studies. The current study investigated localization cues used by two bilateral CI subjects with outstanding localization ability. The first experiment studied localization for sounds of different spectral and temporal c...
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A method to assess the quality of music reproduction in passenger cars is developed and evaluated. In essence, the subject sits in a standing car and is presented from a CD music of different genres via the car?s audio system. The subject has to rate different aspects of the performance on a 10 step scale using a PDA. From the ratings, a net like a...
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Full-text available
A study was designed to examine the effects of frequency components and temporal components and temporal factors on the impression of dangerousness with systematically controlled synthetic sounds, which were applied for stimuli. The frequency was transferred from the low octave to the high in two octaves. Six kinds of frequency components and four...
Chapter
Two different kinds of sound changes are discussed in this chapter. One is the variation that may be compared to variation in water level: there is always some water but the level varies as a function of time. In acoustics, modulations are typical changes of the sort we call variations. The other kind of change is that of differences. One apple may...