Psychoacoustic Aspects Research Articles

Sound from unmanned aerial vehicles in ambient acoustic environments: Influences of context, vehicle characteristics and flight operations on human perception and response

The potential opportunities for unmanned aerial vehicles (UAVs) to offer wide societal benefits are accompanied by risks of introducing novel sources of community noise impact. Accordingly, it is important to develop a greater understanding of the subjective perception and response to UAV sound. Suitable evidence-based strategies for managing the potential risks to public health and wellbeing can then be devised in the form of flight path optimisation tools, to support initial technology deployment efforts. The ‘REFMAP’ project aims to develop these tools, which will include a component enabling noise constraints to be considered. In support of this objective, a laboratory listening experiment has been undertaken to study psychoacoustic aspects of UAV sound exposure. The experiment design incorporated influences of contextual auditory and soundscape factors, by embedding spatially rendered UAV sound events within ambisonic recordings of urban acoustic environments. The UAV renderings comprised varying flight operations and numbers of flight events. The experiment was focussed on determining both perceptual noticeability and affective responses to UAV sound, including noise annoyance. Initial results from the experimental data analysis are discussed, in the context of future planned work within the REFMAP research project.

Ski-hill Graph Pedagogy meter fundamentals acoustics education

Acoustics education in school music classrooms is generally approached as a study of sound as pitch frequencies, spectral analysis, and other elements of music such as rhythm, volume, and timbre. While the psychoacoustic aspects of these acoustic properties continue to inspire and educate, the musical meter is yet to be introduced as an ordinary aspect of acoustics discussions. The meter is taught as notation, time signatures and a beat grouped in a measure, even though the listener may experience a disconnect between what is experienced and what is taught and represented as meter. Combined, the meter’s psychoacoustic role during music experiences is less critical or misunderstood due to the previous lack of meter theory than tonality. Meter theorists and music educators are responding to the call for solutions (Cohn, 2020). To illustrate how meter can be understood and taught through listening to music, as psychoacoustical and mathematical from the earliest lessons, the paper provides a solution to introduce contemporary meter theory (Cohn, 2020) to beginners based on listening experiences. The report discusses the ski-hill graph as applied to meter fundamentals and provides inclusive music education; cross-cultural, multi-sensory applications demonstrate plausible benefits through an interdisciplinary approach to the meter.

Subjective Perception and Psychoacoustic Aspects of the Laryngectomee Voice: The Impact on Quality of Life.

A retrospective study is presented to correlate the inter-judge consistency for the different psycho-perceptual parameters of the recently proposed Impression Noise Fluency Voicing (INFVo) perceptual rating scale for substitution voices, and the vocal function as perceived by the patient. The scale Voice-Related Quality of Life (V-RQoL) and the Self Evaluation of Communication Experiences After Laryngectomy scale (SECEL)-a self-evaluation questionnaire of communicative experience after laryngectomy surgery-were administered to 89 total laryngectomees, subdivided in four groups depending on their type of alaryngeal voice (i.e., tracheoesophageal and esophageal speakers, electro larynx users, voiceless patients), in order to evaluate the impact of the impairment of the phonatory function on the quality of life. No significant differences exist among the various groups on their perception of QoL using subjective questionnaires, whereas the INFVo scale has proven to be a useful tool for the description and analysis of the psychoacoustic characteristics of the vocal signal and a reliable instrument to correctly classify the patients. It is also notable that the judgement of the patients on their own voice and those of the referees are highly significant. Although speech rehabilitation for the acquisition of a substitution voice offers a new way of communication for the laryngectomized patients, nonetheless, their QoL is not significantly related to the type of substitution voice. Therefore, improving the patient's adaptation to the new phonatory condition is mandatory.

Numerical and Experimental NVH Testing of Vehicle Components – from Simple Part to Complex Assembly

Increased demanding in the fields of noise pollution, human comfort and health finds its prints in the development of automotive components. The paper presents general problems of noise and vibration in the vehicles. Main sources and transfer paths are identified. The sound quality – psychoacoustic aspects are also described. In the second part of the article, authors presents an example of numerical and experimental approach to the undercarriage components testing in the field of noise and vibrations problems. Presented examples leads through the basic investigations of particular component to the investigations of complex subassemblies.

Sound quality factors influencing annoyance from hovering UAV

This study investigates psychoacoustic aspects of the noise of multi-rotor type unmanned aerial vehicles (UAV). Two psychoacoustic experiments were performed for a dual purpose: to examine the difference of annoyance induced by the noise from three types of UAVs and a civil aircraft and also to identify the acoustic factors influencing the annoyance from UAV noise. In the first experiment, the annoyance of each stimulus was quantified from psychoacoustic tests and compared with each other. The psychoacoustic tests confirms that UAV noise generally causes more annoyance than civil aircraft noise at the same loudness level. The physical and psychoacoustic indices of the stimuli were analyzed statistically using principal component analysis and regression. The loudness, sharpness and fluctuation strength were derived as significant factors that affect the annoyance of UAV noise. In the second experiment, six new sound samples were created by modifying the sharpness and the fluctuation strength of one representative UAV noise to check the results of the first experiment. Regressions of the test results reaffirmed that the sharpness and fluctuation strength are significant in the annoyance of UAV noise.

Context and perceptual asymmetry effects on the mismatch negativity (MMNm) to speech sounds: an MEG study

ABSTRACTThe mismatch negativity (MMN) of the auditory ERP/ERF has been shown to be sensitive to both phonetic and phonological contrasts. However, potential asymmetry effects and effects of the immediate phonetic contexts on this neural sensitivity are understudied phenomena. Using magnetoencephalography (MEG), we attempted to address this lacuna by investigating native Danish listeners’ MMNm to the phonological contrast between the consonants /t/ and /d/ in two different phonetic contexts in Danish: one word-initial, preserving the contrast’s phonemic status, and another word-final, neutralising it. We found no support for effects of the immediate phonetic context on the MMNm. However, we observed an asymmetry effect for the phonological contrast: Hearing [t] among [d]s elicited a significantly stronger MMNm than hearing [d] among [t]s. This asymmetry effect was mirrored in a behavioural oddball-detection task showing reduced sensitivity for hearing [d] among [t]s. We discuss both psychoacoustic aspects and phonological underspecification as potential explanations.

Guitar amplifier modeling—Perceptual evaluation of audio similarity

Virtual analog modeling of guitar equipment, especially tube-based guitar amplifiers, is a hot topic in sound effect research. However, there are no established standards on the evaluation of the accuracy of such modeling processes. This work presents a first approach on finding a metric for evaluating the similarity between the output of an analog reference amplifier and a digitized version of the same device. A gray-box modeling procedure is used where only assumptions about the general structure of a guitar amplifier are made. The necessary information about the reference device is obtained by input and output measurements. First a digital model is constructed and the error between digital model and analog system is minimized by the Levenberg-Marquardt parameter optimization algorithm. The error is expressed as the result of a cost function. To be able to produce good results, this cost function needs to consider psycho-acoustic aspects like e.g. the perceived frequency resolution. The results of a spectrogram based cost function are compared to the results of a listening test, where the test subjects should rate the similarity of the two audio signals (reference and digital simulation) and the findings are discussed.

Changing seating arrangements of the orchestras - a challenge for the concert hall design

For the future of concert hall design, two aspects will play an increasing role: the search for new shapes created by the architects and changing seating arrangements preferred by the conductors. Whereas in the last decades, acoustic consultants could assume that e.g. celli and double basses were positioned on the right side of the stage, they will to have consider now that more and more conductors - particularly those of high international reputation - go back to the classic seating arrangement (celli in the center, 2nd violins on the right side. Among others, this distinct tendency leads to the following questions: Which are the tonal (acoustic) advantages of the German seating arrangement and by which roomacoustical means can they been supported? In which directions - seen from the player - exist important reflection areas for timbre, clarity and spaciousness? How should risers on the stage be designed for improving the listeners' sound impression and supporting the musicians' mutual hearing? Do celli and basses need podium areas capable of vibrating? Furthermore, where are critical areas and delay times for generating echos or erroneous localization of French horns or other winds? These questions shall be discussed from physical and psychoacoustic aspects.

Significance of Psychoacoustic Aspects for the Evaluation of Vehicle Exterior Noise

For 25 years acoustic engineers have been using specific measurement technologies and analyses to determine sound quality of vehicle interior noise. However, with regard to exterior vehicle noise only standard measurements, e.g. the A-weighted sound pressure level (ISO 362), have been used and interpreted so far. Extensive knowledge and experiences concerning the evaluation of interior noise are still unutilized for an advanced assessment of vehicle exterior noise. Within EU research projects, such as SVEN or QCity, exterior noise was investigated, methods established and psychoacoustic analyses carried out. The relevance of vehicle exterior noise with respect to perceived product quality was underestimated for a long time. Today, manufacturers recognize the importance of exterior noise beyond the annoyance perspective. Vehicle exterior noise conveys an impression of product quality. By optimizing the product sound quality manufacturers can compete against others and meet increased requirements. Customers prefer vehicle sounds which match their expectations, which also applies to the exterior sound of a vehicle. The acoustical fingerprint of a vehicle - inside and outside - provides enormous marketing opportunities. This paper shows how the knowledge of sound quality analyses with regard to interior noise can be transferred to the evaluation of exterior vehicle noise.

Applications of psychoacoustics to information technology products

Emerging usage models for computing devices require low acoustic noise, for example in home entertainment systems. Studies have shown that not only the overall level, but also the psychoacoustic aspects matter. This paper provides an overview of testing techniques that are used in the information technology industry and outlines two specific case studies. First, an extensive subjective psychoacoustic study was designed and conducted in multiple geographies to determine the aspects of sound that best describe the annoyance to sound from information technology products in a home type environment. Over 200 participants in four countries participated in this carefully controlled experiment and rated typical steady state sounds on a 5 point annoyance scale. The relevant sound quality metrics were extracted and geographical variations quantified. Second, in a paired comparison study the influence of modulation on annoyance was investigated by superimposing different frequency and amplitude modulated sounds onto a baseline sound. The results indicate that modulation can have a significant effect on subjective perception.

On the perceptual performance limitations of echo cancellers in wideband telephony

In this paper, standard echo canceller performance measures are evaluated in terms of psychoacoustic aspects of human hearing. The focus is on wideband speech communications systems with long round-trip delays of 200 ms and up present in the transmission path. The results of a simple acoustic echo cancellation experiment are analyzed with a standard psychoacoustic model, revealing that steady-state echo return loss enhancement and mean square error cannot be used to determine whether residual echo is perceivable in the presence of background noise. In addition, a simple modification to the normalized least mean square (NLMS) algorithm is introduced by adding a perceptual preemphasis filter. Simulation results and listening tests show that it is possible to improve the perceived performance of an echo canceller during convergence by placing greater emphasis on frequencies at which the human auditory system is most sensitive.

A human-hearing-related prediction tool for soundscapes and community noise

There are several methods of calculation available for the prediction of the A-weighted sound-pressure level of environmental noise, which are, however, not suitable for a qualified prediction of the residents’ annoyance and physiological strain. The subjectively felt noise quality does not only depend on the A-weighted sound-pressure level, but also on other psychoacoustical parameters, such as loudness, roughness, sharpness, etc. In addition to these physical and psychoacoustical aspects of noise, the so-called psychological or cognitive aspects have to be considered, too, which means that the listeners’ expectations, their mental attitude, as well as the information content of the noise finally influence the noise quality perceived by the individual persons. Within the scope of a research project SVEN (Sound Quality of Vehicle Exterior Noise), which is promoted by the EC, a new tool has been developed which allows a binaural simulation and prediction of the environmental noise to evaluate the influence of different contributions by the sound events with respect to the psychoacoustical parameters, the spatial distribution, movement, and frequency. By means of this tool it is now possible to consider completely new aspects regarding the audible perception of noise when establishing a soundscape or when planning community noise.

Multidimensional acoustical and psychoacoustical aspects of inharmonic plate and bar tones of real and resynthesized instruments

Following a brief review of the mathematics of inharmonic plates and bars, the acoustics and comparative psychoacoustics of the tones of Indonesian bars and plates are considered. Tones were derived from real instruments of the UCLA Department of Ethnomusicology’s Javanese and Balinese gamelans, and from resynthesis of spectral analyses of instrumental tones. The comparative psychoacoustics of the tones was assessed by a number of methods, including JNDs, ratings by MDS similarity-scaling, and verbal-attribute magnitude estimation. Several methods were used to converge on the general perceptual and cognitive properties of the tones. Illustrative findings are: It was shown (1) that Indonesian gamelan makers can and do tune their metallophones in stretched octaves. Their stretchings (1.02 to 1.05 times the normal octave) were fit by a mathematical model which was derived from the data of many gamelans. (2) That the perceptual dimensions of Indonesian and Balinese gongs were interpreted as pitch, ombak (beating), and volume. These dimensions can be mapped to frequency, amplitude modulation, and spectral envelope. It was concluded that gong makers can modify the plates to achieve desired physical properties and correlated perceptual dimensions. One important finding is that the relative positions of two close axially symmetrical modes control the ombak rate.

When bad amplification is good: Distortion as an artistic tool for guitar players

This presentation surveys the development of and the approaches to distortion for electric guitars, which plays an extremely important role in modern popular music, particularly in Rock, Blues, Jazz, and Pop. The signal processing for guitar amplification has always included nonlinear effects that are usually heard as distortion, but also lends other important characteristics to the guitar tone. Originally, distortion occurred as musicians tried to coax more volume out of their amplifiers than they were designed to deliver. However, this ‘‘design flaw’’ soon became a tremendous asset. Guitarists discovered that, if handled properly, distortion gave their instruments an expressive, harmonically rich, and highly controllable voice rivaling that of horn players. Today, distortion for electric guitars has been cultivated to the extent that it is deliberately designed into every guitar amplifier. Characteristics of electric-guitar signals and distortion devices will be discussed and illustrated with examples. The reasons why distortion is a desirable artistic tool and related psychoacoustic aspects also will be discussed.

Resonating Sound Art and the Aesthetics of Room Resonance

Sustained acoustic resonance has been explored by many sound artists and, in some works, it is the central or sole mechanism of sound production. Instances are identified among the work of Ros Bandt, Garlo, Alan Lamb, Alvin Lucier, Gordon Monahan, Roger Winfield and others. In addition to shared formal elements, such works tend to share auditory phenomenological characteristics. It is hypothesised that sustained resonance in general exhibits a type of sound with particular aesthetic connotations, which are largely derived from psychoacoustic factors. This article outlines the terms of and discusses the findings from my experimental investigations into acoustic and psychoacoustic aspects of room resonance. The range of room resonance sounds available from one particular room was explored using a procedure adapted from one of Lucier's works. Listening tests were conducted on the resulting sounds, eliciting descriptive, evaluative and emotional responses from 13 subjects. There are some correspondences between the listening test results and apparent characteristics of resonating sound art.

Human echolocation: The ECOTEST system

The ECOTEST (EChOlocation TEST) is one of the modules of a PC based system — Rousettus — developed in order to study the human echolocation process, i.e. the ability for auditive perception of obstacles without the use of vision. The ECOTEST allows, rapidly and in a flexible way, the construction and management of specially designed auditive perception tests in order to analyse the psychoacoustic aspects of echolocation. Efficient construction of the tests, using real or artificial echolocation signals as sound stimuli, was achieved through the implementation of a specific computational language. The results, which are based on an experiment carried out with 30 sighted subjects and one blind person, indicated that the ECOTEST is a potentially valuable tool for the evaluation, prediction and training of the echolocation ability by the visually handicapped person through auditive perception tests.

Psychoacoustic Aspects of Speech Pattern Coding for the Deaf.

The SiVo aid, which provides a sinusoidal signal indicating voice fundamental frequency and voicing information, was compared as an aid to lipreading to a conventional hearing aid having extended low-frequency output. Speech perceptual measures of consonant confusions in lipreading and the identification of a simple intonation contrast were collected from a group of 8 profoundly deaf adults. Audiometric and psychoacoustic measures were also collected. In the intonation task, 6 of the 7 patients tested performed better with the SiVo aid and the seventh scored perfectly with both aids. Four patients (out of 8) preferred to use the SiVo aid rather than the conventional aid, and 2 of these showed a significant advantage with the SiVo aid in the aided lipreading of consonants. The remaining 4 patients preferred the conventional aid, although none of these patients showed a significant advantage with the conventional aid in the lipreading of consonants. The 4 patients who preferred the SiVo aid over the conventional aid had very profound hearing loss and minimal dynamic range at 500 Hz and above, and those receiving the greatest benefit showed no measurable frequency selectivity. In the 2 patients who preferred the SiVo aid, yet showed no significant advantage for the SiVo aid in consonant lipreading, consonant confusions were also measured for aided lipreading, using a prototype aid providing both voice fundamental frequency and voiceless excitation patterns. Both patients showed additional and significant benefit from inclusion of the voiceless pattern element.

The Concept of Musical Consonance: A Link between Music and Psychoacoustics

This paper is a presentation of the essentials of a new concept and foundation of musical consonance described by the present author in German in Acustica 36,121-137 (1976). Musical consonance is considered from the terminological, musical, conceptual, and psychoacoustic aspects. An appropriate definition of musical consonance is given, based on the principles governing tonal music. Recent results on psychoacoustic evaluation of consonance, which at first glance appear to be in conflict with musical experience, can be reconciled by a two-component concept of musical consonance. The first component is called sensory consonance; it represents the graded absence of annoying factors and is not confined to musical sounds, that is, not music specific. The second component of musical consonance is called harmony; it represents the typical, musicspecific principles of tonal affinity, compatibility, and fundamental-note relation (root). This concept is discussed in the context of Helmholtz's work on Konsonanz and Klangverwandtschaft. Helmholtz's work turns out to be an excellent basis of modern solutions to the consonance problem, as much of it still is valid, while the remainder can readily be replaced by more appropriate new solutions. The psychoacoustic foundations of sensory consonance, as provided by modern psychoacoustics, are largely identical with those found by Helmholtz. With regard to harmony, that is, the music-specific component of musical consonance, a new psychoacoustic foundation is provided by the established principles of virtualpitch perception. Several consequences and prospects of the concept for musical science are briefly considered.

Psychoacoustical aspects of synthesized vertical locale cues.

A new method of studying vertical localization is described whereby the high-frequency response of the external ear is synthesized by a computer program incorporating two variable latency delay and add processes. The resulting sounds were evaluated by presentation to subjects via headphones which bypass the external ear. Vertical movement of the sound source was perceived when the latency of one echo was changed dynamically between 100 and 300 microsecond and this effect required the presence of high-frequency signal components (about around 4 kHz). In further experiments, the variation of perceived elevation with echo delay was measured, and it is shown that the vertical locale of the apparent source is a monotonic function of echo latency in the 160-260 microsecond region. It is proposed that locale is decoded by a form of spectral pattern recognition, whereby the locale of the source is represented as a peak on an autocorrelation function. The time-axis values (between 160 and 260 microsecond) corresponding to these peaks are considered to correspond to vertical locale for elevations between roughly, 60 degrees above horizontal and 40 degree below.

The standardization of monaural phase

This paper redefines and examines the problem of monaural phase distortion in audio systems. Both technical and psychoacoustical aspects of the problem are considered. The redefinition of phase distortion is based upon adopting the acoustical signal at the input of the system as the standard reference. The sources of phase distortion in audio systems are examined with reference to this standard. A review of early and recent psychoacoustic experiments concludes that monaural phase effects can significantly affect the quality of a perceived sound. A signal detection model is used to determine a conservative equivalency between frequency dependent phase distortion and amplitude distortion. It is suggested that a system which maintains a 3 dB tolerance in frequency response should also maintain a 17° tolerance in phase shift. A recent experiment is shown to confirm the conclusion drawn from this model. Absolute phase (polarity error) is evaluated with reference to amplitude distortion in light of recent experiments. It is concluded that at high sound pressure levels absolute phase error is more detectable than 11.5 percent intermodulation distortion. A set of standards for various types of audio equipment is defined, which if implemented would eliminate absolute phase error in audio systems. Finally, the importance of these findings with reference to realism of reproduced sound is commented upon.