Psychoacoustic Evaluation Research Articles

Psychoacoustic evaluation of acoustic features distortion in fricative consonant of speech

The present study investigated the perceptual discrimination between typical (normal) acoustic features duration and intensity in word-initial fricative consonant /ʃ/ and atypical duration (shortened or lengthened) and intensity (weak or strong). Perceptual task distortion contrast was performed in each dimension, duration and intensity, as well as in two-dimensional interaction. Stimulus was the word /ʃuma/ with fricative /ʃ/ in the initial position. Duration and intensity of /ʃ/ were synthesized from typicaly pronounced stimuli in 16-step continuum from 135 ms to 300 ms and from −18 dB to +4.5 dB, respectively. Eight speech-language pathologies (SLPs) performed perceptual task distortion contrast in these two dimensions. Results are presented in the form of identification functions. First experiment tested two-choice decision and three-choice decision tasks in identification of distortion in time domain (shortened/normal/lengthened frictive), second experiment analyzed distortion in intensity domain (weak/normal/strong frictive), third experiment examined mutual interaction of distortion in duration and intensity, and forth experiment analyzed two-dimensional perception of simultaneous distortion in both domains, time and intensity. The results indicate regions of typical and atypical values for duration and intensity of fricative /ʃ/, in Serbian language, and also indicate that distortion in intensity domain does not influence perception of distortion in time domain, except in the case of weak friction. In two-dimensional perception of normal fricative /ʃ/, the dimension duration has higher perceptual significance over dimension intensity, whereas in perception of distorted fricative the dimension intensity has higher perceptual significance over dimension duration. In two-dimensional perception SLPs reported that they selectively recognize at first the dominant distortion and then another distortion.

Voice outcome after type-1 thyroplasty for unilateral vocal cord paralysis: our experience at tertiary care hospital

<p class="abstract"><strong>Background:</strong> Vocal cord paralysis is a clinical sign caused by paralysis of intrinsic muscles of larynx due to dysfunction of recurrent laryngeal nerve or injury to the vagus nerve. One of the common and effective methods of medialization is by using silicone implants. This study was aimed at prospectively assessing and analysing the vocal outcomes and quality of life of patients in type 1 medialization thyroplasty using silicone implants.</p><p class="abstract"><strong>Methods:</strong> Prospective study of 18 months was done on 17 patients with unilateral vocal cord paralysis. Surgical procedure for the patients was standardized by using silicon implant to medialize the cord. The parameters used for the pre and post treatment objective analysis were stroboscopic analysis, psychoacoustic evaluation, maximum phonation time (MPT) and patient’s self-assessment. </p><p class="abstract"><strong>Results:</strong> In our study all 17 patients with unilateral vocal cord paralysis who were subjected to vocal cord medialization using silicone implant showed a statistically highly significant improvement in all the parameters of assessment. The mean preoperative MPT was 7.260 and post-operative MPT showed significant improvement and was 17.428 seconds. mean preoperative GRBAS score was 11.695 and post-operative was 3.826. Similarly, pre op vocal handicap index was 31.173 which decreased significantly after the procedure was 7.695.</p><p class="abstract"><strong>Conclusions:</strong> In the present study, we obtained favourable results of medialization thyroplasty as expressed by objective analysis of voice including GRABS score and acoustic analysis as well as maximum phonation time apart from traditional voice recording.</p><p> </p>

Principles and Methods for Psychoacoustic Evaluation of Tinnitus.

Tinnitus, the perception of sound in the absence of a physical sound in the environment, is highly heterogeneous. It varies in its etiology, characteristics, and impact on an individual's life. The sound is commonly described as "ringing," "buzzing," "crickets," "hissing," "humming." Tinnitus can be acute or chronic, mild or disabling. It can be perceived unilaterally or, more commonly, bilaterally. The sound and its location differ from person to person and fluctuate in the same individual over a certain period of time. This heterogeneity in characterization has important implications for research and clinical practice. Identifying patterns in how tinnitus sounds and its relationship to hearing may aid in identifying different forms of tinnitus and revealing their underlying mechanisms. However, the subjective nature of characterizing tinnitus makes it difficult to reliably define and measure. This chapter will focus on reviewing the psychoacoustic assessment of tinnitus, its relationship to cognitive and behavioral aspects of tinnitus, and its neuropathophysiology. In particular, it will describe the heterogeneity of tinnitus and tinnitus matching, and how individual variability in measures may be used to guide treatment and as a prognostic factor.

Clinical profile and implications of tinnitus in individuals with and without hearing loss.

To compare clinical characteristics of tinnitus and interference in quality of life in individuals with and without associated hearing loss, as well as to discuss the association of quantitative measurements and qualitative instruments. A quantitative, cross-sectional and comparative study approved by the Research Ethics Committee (No. 973.314/CAEE: 41634815.3.0000.0106) was carried out. The responses of the psychoacoustic assessment of tinnitus (intensity, frequency, minimum masking level and loudness discomfort level for pure tone and speech), as well as the Tinnitus Handicap Inventory (THI) questionnaire, and the visual analogue scale (VAS) were compared between 15 patients with tinnitus and peripheral hearing loss (group I) and 16 adults with normal hearing (group II). The mean VAS and THI scores obtained in GI were 5.1 (+1.5) and 42.3 (+18), and in GII, 5.7 (+2.6) and 32.7 (+25), respectively. This result suggests moderate GI annoyance and moderate/mild GII annoyance (p>0.005). There was a positive and moderate correlation between THI and VAS only in GII. In the psychoacoustic evaluation, significant differences were observed between the groups regarding the measurement of loudness (*p=0.013) and the minimum masking level (*p=0.001). There was no direct influence of the presence of hearing loss in relation to the impact of tinnitus. The differences found between the groups regarding the psychoacoustics measures can be justified by the presence of cochlear damage. The objective measurement of tinnitus, regardless of the presence or absence of peripheral hearing loss, is an important instrument to be used along with self-evaluation measures.

Psychoacoustic evaluation of noise emitted by dental air-turbine handpieces

Psychoacoustic evaluation of noise emitted by dental air-turbine handpieces

Method to Estimate the Acoustic Center of Directional Sources and its Psychoacoustic Evaluation

Method to Estimate the Acoustic Center of Directional Sources and its Psychoacoustic Evaluation

Study of the Effect of Splaying Wall to Modify Acoustic Modes Distribution in Small Room

Modes are known as ones of the important acoustical issues in small room. These phenomena could drastically change the spectral and temporal characteristic of sound. Studies have been done in optimizing rectangular room dimension, optimizing source and listener position, and optimizing low frequency with acoustic panel. To follow the best room ratio, a built room has to be cut a lot. This paper is studied the effect of splaying wall in attempt to shift the modes without trimming too much space. Axial room modes from different room ratios – including random, splay wall, Bolt, Louden, Cox – were calculated and compared. Low frequency characteristic of small rooms were observed aided by FEM simulation so that SPL result could be graph and statistically analyzed. It was found that splaying some walls from the random room dimension could distribute the modes evenly, similar with Cox’, though the SPL standard deviation was raised. Further research will be continued through psychoacoustic evaluation.

Psycho-acoustic evaluation of physically-based sound propagation algorithms

Recently, many physically accurate algorithms have been proposed for interactive sound propagation based on geometric and wave-based methods. In terms of these applications, a key question arises whether the improved physical accuracy of these algorithms offers perceptual benefits over prior interactive methods? In this work, we present results from two studies that compare listeners' perceptual response to both accurate and approximate propagation algorithms that are used to simulate two key acoustic effects: diffraction and reverberation. For each effect, we evaluate whether increased numerical accuracy of a propagation algorithm translates into increased perceptual differentiation in interactive environments. Our results suggest that auditory perception indeed benefits from the increased accuracy, with subjects showing better perceptual differentiation when experiencing the more accurate propagation method. The diffraction experiment exhibits a more linearly decaying sound field (with respect to the diffraction angle) for the accurate diffraction method, while the reverberation experiment shows that more accurate reverberation results in better assessment of room volume and acoustic distance perception. In case of room volume, accurate reverberation, after modest user experience, results in a near-logarithmic response to increasing room volume. Finally, in the case of acoustic distance perception, accurate reverberation shows less distance compression as compared to an approximate, filter-based reverberation method.

Prospective analysis of type I thyroplasty using gore-tex implant

<p class="abstract"><strong>Background:</strong> Vocal cord paralysis is a clinical sign caused by paralysis of intrinsic muscles of larynx due to dysfunction of recurrent laryngeal nerve. There are several methods available surgically for the medialisation of the abducted vocal cord. One of the common effective modality is the Gore-Tex medialisation thyroplasty. The results depend on a number of factors including the surgical expertise and extrusion of the Gore –Tex implant. This study is aimed at analysis of all Gore-Tex medialisation thyroplasty done at our centre. Prospectively asses and analyze the vocal outcomes and quality of life of patients in type 1 medialisation thyroplasty using Gore-Tex implant.</p><p class="abstract"><strong>Methods:</strong> Prospective study of 48 months on 30 patients with unilateral vocal cord paralysis. Surgical procedure for the patients was standardized by using Gore-Tex implant to medialize the cord. Video-Laryngoscopy at end of 1<sup>st</sup> month and stroboscopy & voice analysis at end of 3<sup>rd</sup> month post treatment, the parameters used for the pre and post treatment objective analysis are a) stroboscopic analysis, b) psychoacoustic evaluation, c) maximum phonation time, d) patient’s self-assessment. </p><p class="abstract"><strong>Results:</strong> In our study of 30 patients with a follow up period of 48 months, we can conclude as follows – a)unilateral vocal cord paralysis does not have age or gender specificity, b)statistically significant vocal cord palsy affects the left side more by 70%, c)post op Gore-tex medialisation thyroplasty showed a statistically highly significant improvement in psychoacoustic, mean phonation time, d)post op Gore-Tex medialisation thyroplasty showed a statistically significant improvement in videostroboscopic analysis.</p><p><strong>Conclusions:</strong> Psycho acoustic, mean phonation time analysis would complement each other in the assessment of the medialisation thyroplasty thus obviating videostroboscopy.</p>

Efficient and Noise Reduced Design of Axial Fans Considering Psychoacoustic Evaluation Criteria

Axial fans are the largest group of blowers and thus have a significant impact on their environment: Their demand for electrical power and the generation of a significant noise emission, have a negative impact on the environment.In this work the improvement of efficiency and reduction of noise emission are subject of the investigations. Several types of low-pressure axial fans are subject of this investigation. Measurements of pressure rise, efficiency and acoustic behavior will be presented for different blade geometries. The modifications of forward- and backward-skewed blades are compared to a unskewed blade geometry. The forward-skewed configurations show an improvement on the hydraulic properties, the efficiency and reduce the noise emission whilst the backward-skewed configurations improve the acoustic behavior at low flow rates with flow detachment occurring. Besides an acoustic quantification of the noise emission using the sound power level, psychoacoustic methods like loudness and sharpness were used.

Efficient and Noise Reduced Design of a Side Channel Blower Considering Psychoacoustic Evaluation Criteria

Commonly used turbo machines like axial fans or side channels blowers have a large impact on their environment: Large demand for electrical power and production of strong aeroacoustic sound sources, generating a significant noise emission, lead to a environmental footprint. The current work addresses both tasks: improvement of efficiency and reduction of noise emission. In this work a side channel blower is in the focus of the investigations. Since the noise emission of side channel blowers mainly occurs in the region of the stripper, pressure measurements on the blade surface are performed. The pressure trend during the blade passage along the stripper provides information on the exact location of and the contribution to the acoustic noise generation. Modifications of the stripper geometry with the objective of pressure drop linearization along the stripper are evaluated with respect to efficiency, pressure rise and noise reduction. All acoustic measurements are also evaluated with psychoacoustic quantities, like loudness and sharpness, to account for the human perception.

Psychoacoustic Evaluation of the Effects of Aging

Many older adults experience difficulties in complex listening environments that exceed expectations based on their audiometric thresholds. Review of past study of the auditory abilities of older adults indicates that age-related deficits are found primarily for aspects of temporal processing, with task complexity and uncertainty often increasing the effect of aging on performance. In many studies, but not all, significant association has been found between psychoacoustic measures of temporal processing and both speech-in-noise abilities and cognitive status. Intended for clinical use, a brief procedure for evaluating psychoacoustic discrimination of static and dynamic spectral patterns is discussed. Along with showing a deleterious effect of aging on task performance, results indicate significant association between discrimination ability and the cognitive status of older adults. In preliminary evaluation of longitudinal data, the rate of decline in global cognitive status was significantly associated with baseline discrimination of dynamic spectral patterns. These results are consistent with the prominence of age-related deficits for temporal processing with stimulus uncertainty increasing the psychoacoustic effect.

Thermo-acoustic performance of full engine encapsulations – A numerical, experimental and psychoacoustic study

This paper presents the development and investigation of a thermo-acoustic encapsulation for a diesel engine by means of a combined approach of thermo-acoustic recordings, numerical simulations and psychoacoustic evaluation. The encapsulation is positioned in close proximity to the engine and completely surrounds the entire engine block. Experimental tests are performed with the help of an acoustic engine test bench, where the surface of the engine is observed by infrared cameras and the sound is monitored by a microphone-array. Thermal and acoustic measurements of the engine without an encapsulation are recorded and used as reference data for simulations to evaluate and improve the functionality of different design concepts of the encapsulation in comparison to the same engine without encapsulation. The received experimental results are also used to select proper materials as well as to design the heat insulating and sound absorbing encapsulation. Based on the experimental investigations, some weak points of the first prototype are identified. These experimental findings, as well as numerical simulations of the sound radiation, are used as a basis for further design improvements to the encapsulation. The new design that is developed shows a significant improvement in the insulation of the car engine, both thermally and acoustically. In the last step, the perception of the engine sounds are evaluated by measuring changes in the perceived loudness and sound preference of the engine with and without encapsulation by human participants. This allows for a more objective evaluation of the acoustic behavior of the developed engine encapsulation.

Psychoacoustical evaluation of natural and urban sounds in soundscapes

Among various sounds in the environment, natural sounds, such as water sounds and birdsongs, have proven to be highly preferred by humans, but the reasons for these preferences have not been thoroughly researched. This paper explores differences between various natural and urban environmental sounds from the viewpoint of objective measures, especially psychoacoustical parameters. The sound samples used in this study include the recordings of single sound source categories of water, wind, birdsongs, and urban sounds including street music, mechanical sounds, and traffic noise. The samples are analyzed with a number of existing psychoacoustical parameter algorithmic models. Based on hierarchical cluster and principal components analyses of the calculated results, a series of differences has been shown among different sound types in terms of key psychoacoustical parameters. While different sound categories cannot be identified using any single acoustical and psychoacoustical parameter, identification can be made with a group of parameters, as analyzed with artificial neural networks and discriminant functions in this paper. For artificial neural networks, correlations between network predictions and targets using the average and standard deviation data of psychoacoustical parameters as inputs are above 0.95 for the three natural sound categories and above 0.90 for the urban sound category. For sound identification/classification, key parameters are fluctuation strength, loudness, and sharpness.

Psychoacoustic Evaluation Model on the Luxury of Sound Quality in Vehicle Interior Noise

This paper studied the comprehensive evaluation index of sensory luxury of Sound Quality in Vehicle interior noise. The relationship between it and psychoacoustic parameters under different conditions was studied. Four types of vehicle real-time noises were recorded at several running speeds and later were subjectively evaluated in the testing room by semantic subdivided method. According to the subjective test and evaluation, the psychoacoustic objective quantificational model was built using correlation analysis and multi-dimensional linear regression analysis. The results indicated that: the luxury of vehicle interior noise showed good correlation with loudness and sharpness. The luxury increased as loudness or sharpness decreased, but it decreased as speed increased.

Psycho-acoustic evaluation of the indoor noise in cabins of a naval vessel using a back-propagation neural network algorithm

The indoor noise of a ship is usually determined using the A-weighted sound pressure level. However, in order to better understand this phenomenon, evaluation parameters that more accurately reflect the human sense of hearing are required. To find the level of the satisfaction index of the noise inside a naval vessel such as "Loudness" and "Annoyance", psycho-acoustic evaluation of various sound recordings from the naval vessel was performed in a laboratory. The objective of this paper is to develop a single index of "Loudness" and "Annoyance" for noise inside a naval vessel according to a psycho-acoustic evaluation by using psychological responses such as Noise Rating (NR), Noise Criterion (NC), Room Criterion (RC), Preferred Speech Interference Level (PSIL) and loudness level. Additionally, in order to determine a single index of satisfaction for noise such as "Loudness" and "Annoyance", with respect to a human's sense of hearing, a back-propagation neural network is applied.

Psycho-acoustic evaluation of the indoor noise in cabins of a naval vessel using a back-propagation neural network algorithm

The indoor noise of a ship is usually determined using the A-weighted sound pressure level. However, in order to better understand this phenomenon, evaluation parameters that more accurately reflect the human sense of hearing are required. To find the level of the satisfaction index of the noise inside a naval vessel such as “Loudness” and “Annoyance”, psycho-acoustic evaluation of various sound recordings from the naval vessel was performed in a laboratory. The objective of this paper is to develop a single index of “Loudness” and “Annoyance” for noise inside a naval vessel according to a psycho-acoustic evaluation by using psychological responses such as Noise Rating (NR), Noise Criterion (NC), Room Criterion (RC), Preferred Speech Interference Level (PSIL) and loudness level. Additionally, in order to determine a single index of satisfaction for noise such as “Loudness” and “Annoyance”, with respect to a human’s sense of hearing, a back-propagation neural network is applied.

The Subjective Assessment of Soundscape in Campus — Taking YaoHu Campus of Jiangxi Normal University for Example

In order to the search for more effective noise control measures and a more rational urban planning from the angle of economy, environment, so that we can create a healthier living environment, this paper does some preliminary investigation in the aspect of soundscape. This paper introduces soundscape science research status and research results domesticity and abroad, and on this basis, makes a subjective evaluation of voice of the landscape in Jiangxi Normal University, by combinating Psychoacoustic Evaluation Method. This paper record various of sounds existing in the campus, analyses properties of each sound, and does a large-scale survey about the popularity of these sounds. The paper chooses ten most popular voices using mark-giving method, and analyses the ten 10 kinds of sound by SD methods. The following are the results: (1) the ten most popular voices in the campus: voice of birds, sounds of musical instruments, voice of singing、reading、and teachers’ lectures, and the sound of radio(music)、 broadcasting (in English and other programs)、computer sound (music, film sound) and wind，50% of which are natural sounds, 30% human voice, and 20% noise of machines. From above, we can see that the sounds from nature are more acceptable. (2) By using semantic differential method (SD Act), the paper does a subjective evaluation on the ten popular kinds of voices. Marks are different form different analysing angle, that is, different people like different voices on different degrees. (3) When people work and learn, it is good to create some comfortable sounds in the surroundings and control or eliminate noisy sounds. Creating a comfortable sound surrounding environment is a good way to improve people’s working and learning effeciency.

木質構造の床衝撃音の「うるささ」の心理音響評価

木質構造で発生する床衝撃音は種々の周波数成分を含む騒音となることがある。そのような場合，「音の大きさ」を指標とするだけでは床衝撃音の「うるささ」を評価することは難しい。本研究では，木質構造の床衝撃音の「うるささ」を評価する新たな指標を見出すことを目的とした。フローリング，衝撃緩衝材，遮音材および厚物合板で構成される木造モデル床を木造軸組構造の上に構築し，各種の衝撃源によって発生させた床衝撃音を収録した。これらの収録音について，「音の大きさ」，「音の鋭さ」および「うるささ」に関わる主観評価を行うとともに，心理音響評価を行った。その結果，床衝撃音の「音の大きさ」，「音の鋭さ」および「うるささ」に関わる主観評価の間には，互いに高い相関があることがわかった。また，床衝撃音の「うるささ」は，心理音響指標の「非定常ラウドネス」と「シャープネス」の線形結合でモデル化できることが明らかとなった。

Psychoacoustic evaluation of multichannel reproduced sounds using binaural synthesis and spherical beamforming

The binaural auralization of a 3D sound field using spherical-harmonics beamforming (SHB) techniques was investigated and compared with the traditional method using a head-and-torso simulator (HATS). The new procedure was verified by comparing simulated room impulse responses with measured ones binaurally. The objective comparisons show that there is good agreement in the frequency range between 0.1 and 6.4 kHz. A listening experiment was performed to validate the SHB method subjectively and to compare it to the HATS method. Two musical excerpts, pop and classical, were used. Subjective responses were collected in two head rotation conditions (fixed and rotating) and six spatial reproduction modes, including phantom mono, stereo, and surround sound. The results show that subjective scales of width, spaciousness, and preference based on the SHB method were similar to those obtained for the HATS method, although the width and spaciousness of the stimuli processed by the SHB method were judged slightly higher than the ones using the HATS method in general. Thus, binaural synthesis using SHB may be a useful tool to reproduce a 3D sound field binaurally, while saving considerably on measurement time because head rotation can be simulated based on a single recording.