Evaluation Of Loudness Research Articles

The Influence of Users' Behavioral Characteristics on Soundscape in the Waiting Halls of Railway Stations

It has been demonstrated in previous studies that the evaluation of soundscape was influenced by not only social characteristics but also some behavioral characteristics of persons. In this study, more than 600 questionnaire survey has been undertaken at waiting halls of 4 railway stations in capital cities of China, to determine how the users’ behavioral characteristics influence their evaluation of soundscape. The results show that the relationships between evaluation of acoustics and passengers’ waiting time, rest or partners is not significant (p>0.1), but visiting times (p<0.01). The evaluation of subjective loudness is the highest, when waiting time at 1.5 to 2 hours, while evaluation of subjective loudness is general lower at other time. The evaluation of acoustic comfort is more different between sitting and standing, when waiting time at 0.5 to 1 hour. The passengers with no partner will give general higher acoustic comfort at first (<0.5 hours), but give lower acoustic comfort at following time.

Influence of SPL distribution on loudness impression for environmental noise

To realize comfortable living environment, it is necessary to reduce the environmental noise according to the suitable environmental noise evaluation index. For considering the environmental noise evaluation index, it is important to know characteristics of loudness evaluation toward long-term noise because the environmental noise was evaluated for long-term. In this study, to investigate the evaluation characteristics, we focused on the distribution of sound pressure level in duration of environmental noise and performed loudness evaluation test using long-term noise by changing the distribution. In the test, four traffic noises in duration of 10 min which loudness was adjusted equality by pre-processing were employed as base sounds. In addition, modified four noises in which the deviation of sound pressure level were increased (the mean value was same as the base sounds) were used as target sounds. Fourteen subjects evaluated the loudness of eight traffic noises immediately after hearing each sound. As a result, it was found that loudness impression toward the target sound was evaluated to as softer than the base sound. Consequently the long-term sound having large deviation of sound pressure level was clarified to be evaluated softer than the sound having small deviation.

Interaction between vehicle exterior design and perceived loudness of vehicle acceleration sound

To increase cabin comfort, not only decreasing sound pressure level but also improving the sound quality is essential. In addition, when the sound quality of the vehicle matches with the exterior design, the sound is considered to be perceived more attractive. In this study, to investigate the relationship between the perceptions of the sound and the exterior design, the loudness of acceleration sounds were evaluated with vehicle exterior images. In the loudness evaluation test, 10 acceleration sounds and 10 exterior images were prepared and half of the images were luxury vehicle images and the others were sporty vehicle images. The experimental subject evaluated the loudness of presented sound with the luxury or sporty vehicle exterior image. Twenty one male subjects participated in the test. Eleven of them drove vehicles frequently and the others were infrequently. As a result, frequently driving subjects felt the acceleration sound louder by having luxury vehicle impression. In contrast, infrequently driving subjects felt the sound softer by having the same vehicle impression. Consequently, it was clarified that perceived loudness was influenced by vehicle exterior design, and the tendency was changed depending on the driving frequency.

Soundwalking을 통한 제주도 올레길의 소리풍경 조사

본 논문은 최근 제주도의 관광상품으로 각광받고 있는 올레길의 소리풍경을 soundwalking을 이용해 조사하였다. 이를 위해 올레길의 전체 16개 코스 중 3개 코스의 10개 지점에서 발생되는 소리의 특징을 문장으로 기술하고 소리의 크기를 측정하는 한편 녹음하였다. 또한 관광객 32명 및 음향전문가 5인을 대상으로 설문을 수행하여 해당지점의 배경 소리의 크기와 불쾌감에 대해 조사하였으며, 설문조사를 통해 인공음 및 자연음 17개를 제시한 뒤 그 중 가장 크게 들리는 소리 및 불쾌하게 들리는 소리, 듣기 좋은 소리와 인상적인 소리를 응답하도록 하였다. 또한 현장에서 녹음해온 소리를 실험실에서 청감실험을 통해 평가하여 현장 실험결과와 비교하였다. 실험 결과 제주도 올레길에서 가장 많이 발생하는 소리는 파도 및 바람소리, 자동차 소음과 사람의 말소리였으며, 그 중에서 듣기 좋은 소리는 자연음으로 이루어져있고 불쾌한 소리는 인공음인 것으로 나타났다. 현장에서 녹음해온 음원 및 영상을 통해 실험실에서 주관적 평가를 수행한 결과 소리의 불쾌감에 영향을 미치는 것은 인공음과 자연음의 비중이며 이는 곧 소리의 크기에 대한 평가에도 영향을 미친다는 것을 알 수 있었다. 그리고 현장평가와 실험실 평가 모두 소리의 크기와 불쾌감에 매우 큰 상관관계가 있음을 알 수 있었다. The present study aims to investigate the soundscapes of Jeju olle route through the soundwalking. In order to do this, sound measurements and sound recording were undertaken at 10 points along Jeju olle route. Also, loudness of background sound and figure sound were examined. Subjective surveys were carried out using questionnaire and interviews with 32 tourists and 5 acoustical specialists in order to investigate the loudest sound, most pleasant and unpleasant sound, and impressive sound among 17 natural and artificial sounds. Additionally, laboratory experiments were achieved to evaluates sound that have been recorded at the field using same questionnaire and the results were compared with those of field experiments. As a result, the sound heard most in Jeju olle route is the sea wave sound, wind sound, automobile noise, and human voice. It was revealed that the most pleasant sound consisted of nature sound among them, and that unpleasant sounds are artificial sounds. The results of subjective test denote that unpleasant sound is affected by ratio of artificial sound and nature sound. And this also affects the assessment about the loudness of the sound. Also, it was found that the results of both field test and laboratory test are closely correlated in the evaluation of loudness of sound and unpleasant feeling.

Influence of Train Colour on Loudness Judgments

This study replicates an experiment described by Patsouras et al. [5] or Rader et al. [8] in which subjects had to evaluate the loudness of a passing-by train noise while watching pictures of the train, the colour of which being varied. In contrast to these studies, no influence of train colour on loudness evaluation could be found. This discrepancy might be due to cultural differences (French subjects vs. German or Japanese ones). But a more realistic reason can be a jury sampling effect, as this influence can exist for very few subjects (one among twenty-two in this experiment).

Loudness models applied to technical sounds.

Loudness evaluation has become a central focus for assuring better consideration of subjective sound intensity phenomena than frequency-weighted levels such as dB(A). Different standards are available for evaluating loudness of stationary sounds (ANSI, ISO, and DIN). In principle, standards are very helpful in daily life, even if the method does not consider the most recent research results. But a variety of standards generating different results, at least for the most important technical or industrial sounds, may lead to confusion. Considering that most of these sounds are time variant, a single model of time-varying loudness is preferable. At present the recently published extension of the German standard for time-varying loudness (DIN 45631/A1) is the sole standardized method, applicable also for stationary sounds. There are other models allowing for loudness evaluation of time-variant sounds. Some years ago, a Hearing Model was borne out of a widespread interest to have a single standardized psychoacoustic model describing and explaining many phenomena at once. The Hearing Model is based on the physiology of human hearing and has been validated by testing against previously conducted psychoacoustic research results. The different methods will be compared and validated with subjective tests using technical sounds.

EVALUATION OF NONSTATIONARY VEHICLE PASSING LOUDNESS BASED ON AN ANTINOISE WAVELET PRE-PROCESSING NEURAL NETWORK MODEL

A new technique for sound loudness evaluation, the so-called antinoise wavelet pre-processing neural network (ANWT-NN) model, is presented in this paper. Based on passing vehicle noise, the ANWT-NN loudness model combines the techniques of wavelet analysis and neural network regression and classification. A wavelet-based, 21-point model for vehicle noise feature extraction is established. Verification shows that the trained ANWT-NN models are more accurate and effective than the WT-NN models for sound quality evaluation of nonstationary vehicle noises. The newly proposed ANWT-NN model can be applied to both the stationary and nonstationary sound signals and even to the transient ones. The ANWT-NN technique is suggested not only for the prediction, classification, and comparison of the sound quality of passing vehicle noise, but also for applications in other sound-related engineering fields, in place of the conventional psychoacoustical models.

Antioxidant Therapy in Idiopathic Tinnitus: Preliminary Outcomes

Reactive oxygen species (ROS) play an important role in several pathogenic processes, damaging various structural and functional cellular components. The endothelium is at major risk of radical-induced lesions and this damage is most manifest in microcirculation. It has been recently observed that ROS are implicated in the pathology of the inner ear and the peripheral and central pathways. In a previous study we detected high serum values of ROS in subjects with idiopathic tinnitus. The purpose of the present study was to evaluate the validity of antioxidant treatment in tinnitus sufferers with high ROS values. The study considered 31 consecutive patients with unilateral idiopathic tinnitus. The mean pure tone audiometric threshold (PTA), tinnitus loudness, subjective disturbance level [visual analogue scale (VAS) determination], and the indirect ROS dosage 48 h before and after medical treatment were evaluated. Patients underwent an 18-week oral treatment with a mix of phospholipids and vitamins (glycerophosphorylcholine, glycerophosphorylethanolamine, beta-carotene, vitamin C, vitamin E). ROS levels were significantly reduced following antioxidant treatment (malonaldehyde: 2.10 vs. 1.98 mumol/dL, p = 0.003; 4-hydroxynonenal: 2.36 vs. 2.16 mumol/dL, p = 0.002) In addition, great improvement was observed in the reduction of tinnitus (VAS and tinnitus loudness evaluations). No significant changes in audiometric threshold occurred. Oral antioxidant therapy in patients with idiopathic tinnitus seems to reduce the subjective discomfort and tinnitus intensity and may be considered as an additional treatment modality.

Loudness estimation in the presence of vertical vibrations

The goal of the study was to check whether vibrations submitted to a subject can modify his loudness evaluation. For that purpose, the subject was seated on a rigid chair vertically moved by a shaker, at the frequency of 28 Hz and at 6 different levels. He was also exposed to a pure sound: either a 28 Hz tone produced by a subwoofer, or a 1000 Hz tone produced by headphones. For each combination of sound and vibration levels, the subject had to estimate the magnitude of the loudness of the tone, as compared to a reference tone, heard without any vibration excitation. He also had to evaluate the magnitude of vibration using a 10 point scale. Twenty subjects participated in the experiment. The results showed that vibrations did not influence loudness estimation. On the other hand, the estimation of vibration level was significantly influenced by the level of the 28 Hz pure tone, which can indicate an interaction between the perception of sound by the body and the perception of vibrations.

Evaluation of subjective loudness rating scale based on conversation disturbance

Evaluation of subjective loudness rating scale based on conversation disturbance

Tinnitus and otosclerosis.

Fifty patients with otosclerosis and tinnitus were studied for the course of the tinnitus after stapes surgery. Tinnitus disappeared in 64% of the cases, improved in 16%, was unchanged in 14%, and worsened in 6%. The reduction in tinnitus was more favorable after a small fenestra stapedotomy than after a partial stapedectomy with removal of the posterior half of the footplate. An unfavorable postoperative course of tinnitus did not appear to be linked to the postoperative audiometric result. In our study the subjective evaluation of pitch and loudness of the tinnitus did not provide significant information regarding its prognosis.

Loudness evaluation of urban soundscapes by a cross-modal matching method

In a previous study, loudness of a time-varying pure tone was evaluated using a cross-modal matching method. In this procedure, the loudness was matched to an equivalent muscular force. Subjects had to judge the instantaneous and global loudness using a proprioceptive input device with force feedback. Using this technique, subjects could respond easily, rapidly, continuously, and with feedback concerning their evaluation. The present study examines the relation between instantaneous and global loudness of 16 urban soundscapes lasting about 20 s using the same method. First, the procedure is individually calibrated with 1-s soundscapes presented at different sound-pressure levels. The data obtained for each subject fit well with a linear relation on a log–log scale between the sound-pressure level in dB and the associated force in log Newtons. Then, the global judgments are performed under two experimental conditions: one with instantaneous loudness evaluation during stimulus presentation and one without. Good correlation was found between these two judgments. The global judgment and the average over the instantaneous matching contour are nearly identical. In addition, a fluction factor (FI) calculated on the loudness judgment contour reflects the degree of movement produced by the subject as well as the presence of discriminable sources.

Effect of time distribution of energy on loudness evaluation

Most work on loudness have been done on stationary sounds. However, environmental sounds are usually temporally variable, and memory effects could be important in loudness evaluation of long-lasting dynamic sounds. The loudness of one-minute sounds containing a local dominating peak of energy was measured. The sounds differed only by the temporal position of the peak. The influence of peak location on the global loudness judgment was evaluated. The global loudness was first evaluated using magnitude estimation. Contrary to expectations, mean estimations were the same for all sounds regardless of peak distribution. In a second experiment, subjects had to judge the loudness, using cross-modal matching. They matched the size of a circle on a computer screen with the loudness of the sound. At the end of the signal, a global estimation was also made using the same cross-modal matching paradigm. This global estimation was made either just after the sound or after a pause of one minute. During the pause, the subject had to perform a distracting task. Relations between global and continuous judgments are discussed. The study can help to design a model of the loudness of temporally variable sounds.

Some new considerations on the perception of subjective loudness in concert halls

The link between the perception of subjective loudness and the total sound level, G, and, more generally, the ambient sound power level at the listener’s ears, has been established for some time. However, new results from laboratory experiments as well as real-hall listening tests indicate that the link is slightly more complicated. These studies suggest that the auditory system monitors the strength of the early part of the room response (corresponding to a perceptual factor of ‘‘presence‘‘) and the late part of the room response (corresponding to a perceptual factor of ‘‘room effect’’) separately. Evaluation of subjective loudness occurs only at a higher level of the auditory system. The results corroborate other investigations in showing that listeners can evaluate different contributions of the room in separate streams of attention.

A New Method for Loudness Evaluation of Noises with Impulsive Components

A New Method for Loudness Evaluation of Noises with Impulsive Components

Loudness evaluation of sounds transmitted through walls—basic experiment with artificial sounds

A basic psycho-acoustic experiment was performed in order to establish a reliable method for evaluating insulation properties of building walls against airborne sound. Eleven models were used to represent actual sound insulation characteristics and three models used for incident noises on walls. Results of a four-step hearing test were arranged according to five well-known measures for noise assessment, and Perceived Level ( PL) was found to be the best among them for assessing the loudness of the sound transmitted through walls. In addition, arithmetic mean values of the sound pressure levels in octave bands from 63 Hz or 125 Hz to 4 kHz were examined. It was found that such simple measures have an unexpectedly high correlation with the loudness, surpassing even the PL. This suggests that the arithmetic mean value of the sound transmission losses in octave bands is a good single-number measure for rating the airborne sound insulation performance of walls.

Clinical studies on the loudness of tinnitus

It is very important to evaluate the loudness of tinnitus adequately for the appropriate treat ment.The loudness balance test and masking test are commonly used for the evaluation of tinnitus loudness. In this report, the subjective loudness level of tinnitus was compared with the loudness level of tinnitus measured by the above two tests and also with the pure tone threshold in 211 patients with tinnitus.The subjective loudness of tinnitus in these cases was classified into five degrees (very soft (0) to very loud(4)). Thus the subjective loudness level measured by these two tests was expressed by two levels which were the audiometer level and the sensation level.The following results were obtained:1) The tinnitus loudness expressed by the sensation level in these two tests is not useful when the tinnitus loudness is compared in the individual cases. Because the loudness of tinnitus is often estimated much smaller by the influence of recruitment and the technical error of these tests in the 5 dB step measurement method is large.2) The tinnitus loudness expressed by the audiometer level changed almost in parallel with the pure tone threshold. Therefore, it is speculated that the tinnitus loudness, expressed by the audiometer level can not be the true tinnitus loudness level.3) The subjective loudness of the tinnitus seems to be increased with the deterioration of the pure tone threshold.4) From these results, both the loudness balance and masking tests are thought to be unsuitable for evaluating the tinnitus loudness. A more appropriated method should be made to evaluate tinnitus loudess adequately.

両側性感音難聴耳における耳鳴のラウドネスの評価

両側性感音難聴耳における耳鳴のラウドネスの評価

A consideration on the loudness of impact sound

In order to investigate loudness of impact sound, the data of about thirty samples of impact sound in our daily life, were collected in prior to laboratory experiments. As the results of the analysis of these sounds, the following ranges were observed: peak level: up to 130 dBA; rise time (from start of a sound to its peak): 0.3–30 ms; decay time (from peak down to −20 dB): 5–500 ms. Referring to these findings, we designed an impact sound generator. In the experiments the effects of these factors on loudness of model impact sounds were studied by the use of the method of adjustment. The peak level of 80–100 dB, the rise time of 0.5–20 ms/60 dB and the decay time of 60–1000 ms/60 dB were treated as the experimental factors. As the results, PL dB, calculated from the peak level r.m.s. circuit with τ = 4.0 ms and 1/3 oct. band energy level was found to be an appropriate unit for loudness evaluation, and the energy of a single burst, Len, was a simple and good measure, too. [Work supported by the Ministry of Education.]

Loudness evaluations of electric clock noise

The noise from consumer electric clocks was studied to evaluate loudness estimating procedures. Eight different clock noises were tape recorded for presentation to a panel of people for loudness judgments. An electronic switch enabled the recorded clock noise and a 1000 Hz tone to be presented alternately via earphones for 1 2 -sec durations with 1 2 -sec silences between signals. The subjects adjusted the 1000 Hz tone to match the loudness of the clock noise. It was determined that Stevens' MARK VI procedure generally underestimates the observed loudness, but is usually less than 10 phons in error. It is possible that biasing effects had some influence on this result. If ranking on a relative loudness scale is all that is desired, dB(A) measurements will suffice. However, the dB(A) measurements do underestimate the differences in loudness between the quietest and loudest clocks.