Evaluation Of Loudness Research Articles

A loudness evaluation test of environmental noises with complex frequency characteristics: a comparison of A-weighted sound pressure level and Moore-Glasberg loudness level

Noises generated from HVAC systems and machinery have complex frequency characteristics that include various frequency components such as tonal components. In order to evaluate and cope with these environmental noises appropriately, it is necessary to apply a noise evaluation index that fits well with psychological responses. In this study, the authors focused on loudness, the most primary aspect of psychoacoustics, and conducted a evaluation experiment using actual recorded sounds. The results of the loudness evaluation were examined using two noise evaluation indexes: A-weighted sound pressure level and Moore-Glasberg loudness level dictated by ISO532-2. As a result, the Moore-Glasberg loudness level showed better agreement with the evaluated loudness regardless of the type of the sound stimuli.

Can an artificially generated sound design improve the subjective evaluation of a vacuum cleaner noise? Results of a listening test with two vacuum cleaners.

In this study, the sound of two vacuum cleaners was enhanced with a psychoacoustic based, artificially generated sound design. One sound design with a lower level (SD_quiet) and one with a higher level (SD_loud) were tested in addition to the condition without sound design (RB). A listening test with 32 subjects was used to evaluate if the added sound design improves subjective evaluation of loudness, annoyance, and noise quality. The results showed a significant difference between the subjective ratings of SD_loud and the subjective rating of RB for both vacuum cleaners. The operating noise with added sound design SD_loud was rated as more powerful, of higher quality, more efficient, and less howling. For one vacuum cleaner, although SD_loud was rated as significantly louder and had a higher sound pressure level than RB, it was not rated as more annoying. This shows the high potential of the use of artificially added sound design in household appliances. Furthermore, the investigation showed that a sufficient volume for an added sound design has to be chosen because there were less differences between SD_quiet and RB regarding the subjective evaluation.

Simulation of aeroacoustic pressure on a vehicle glass with turbulent inflow

Cabin noise of a C-segment hatchback vehicle was measured with an inflow velocity in a proving ground at 120km/h and 160km/h. The recorded data is cut and classified into loud and quiet parts of 10 seconds by a subjective and specific loudness evaluations. In 120km/h case, time-averaged inflow velocity is about 10km/h higher in the loud section than in the quiet section, and the turbulence intensity is higher by 2%. Hydrodynamic and acoustic pressure on glass surfaces are calculated by a CFD and acoustic simulation with and without inflow turbulence in order to evaluate increase in aeroacoustic input due to fluctuation in the inflow velocity. Fluctuation in pressure on glass surfaces increases with the inflow turbulence.

Reliability of parental reporting of child snoring in children referred for obstructive sleep apnea.

Despite the high number of studies based on subjective reports of snoring, self-reported snoring has hardly been validated at all. As there is no "gold-standard" for objective snoring measurements, studies must evaluate whether the presence of snoring based on parental judgement is linked to objective measurements of nasal and/or pharyngeal obstruction in children referred for obstructive sleep apnea. A total of 146 children (median age 11 years) underwent polysomnography (with snoring recording using nasal cannula signal), acoustic rhinometry and pharyngometry, while their parents filled out the Spruyt-Gozal questionnaire assessing both frequency and loudness of subjective snoring. Three categories were further differentiated (null, low and high) for both frequency and loudness. The apnea-hypopnea index was significantly different in the three groups for both frequency (p=0.04) and loudness (p=0.01) of subjective snoring. Children in the low or high groups (frequency or loudness), compared with those in the null group, experienced a decline in both pharyngeal (sitting and supine positions) and nasopharyngeal (supine position) volumes (frequency, pharynx sitting: p=0.03; supine: 0.005 and nasopharynx: p=0.002; loudness, p=0.03; p=0.007 and p=0.03; three group comparisons). Objective snoring frequency during the night obtained with cannula was weakly related to loudness of subjective snoring but not to subjective snoring frequency during the week, and was biased by nasal obstruction. In conclusion, our study showed that parental assessment of snoring is related to a reduction in both pharyngeal and nasopharyngeal volumes in snorers, arguing for the adequacy of their evaluation of both snoring frequency and loudness.

Influence of Color on Loudness Perception of Household Appliances: Case of a Coffee Maker

Previous studies have investigated the effect of color on the assessment of loudness in various cases, such as cars, trains, and concert halls. This study sets out to explore the influence of color on the loudness perception of household appliances, in particular in the case of coffee makers. To this end, images of a coffee maker colored in black, red, dark green, light blue, light green, and white were displayed to participants during a magnitude estimation task. In a repeated measures design, the sound of a coffee maker was used synchronously as a stimulus presented in different sound levels (74, 78, 82, and 86 dB LAeq). The sample of participants was selected to be gender balanced and unfamiliar with similar experiments. Statistical analysis suggested that the color of the visual stimulus had no influence on loudness judgments. However, a gender-based statistically significant influence regarding the color of the coffee maker on loudness evaluation was found for females. An interpretation of the results is attempted in the discussion. The results of this study suggest that since there is the possibility of gender differences in the assessment of loudness for household appliances, special care should be taken in similar studies to account for these effects. Finally, these gender differences could possibly be utilized for product sound design and product marketing where the appropriate use of color has been found to be effective.

Difference in the perceived loudness of sound between Chinese men and women

Gender differences in perceived loudness have been observed between Japanese men and women in previous studies. Female participants tended to assign higher loudness scores to sounds of the same sound pressure level than did male participants. However, this difference was not clearly observed when using a ratio scale for the evaluation of loudness, such as in a magnitude estimation. To discuss factors affecting gender differences in perceived loudness, the same rating experiments used in previous studies were conducted with Chinese men and women. A rating experiment using a verbal interval scale showed that Chinese women tended to rate the same sounds as louder than did Chinese men. The gender effect was replicated in an experiment using an adjustment method that measured the limits of the sound pressure level perceived as soft or loud; women selected lower levels than did men for the highest limit of soft sounds and the lowest limit of loud sounds. These tendencies were the same as those of Japanese men and women observed in previous studies. Rating experiments adopting the methods of magnitude estimation and magnitude production for the ratio scales showed that the power exponent a in Stevens' power law was larger for female participants than for male participants under some conditions. However, the observed gender difference in the power exponent a for Chinese was not consistent, while it was not clear for Japanese. The gender difference in criteria for verbally categorizing loudness may be responsible for the gender difference in perceived loudness.

The Effect of Voice Therapy for the Treatment of Functional Aphonia: A Preliminary Study

Background and Objectives Functional aphonia refers to in which by presenting whispering voice and almost producing very high-pitched tensed voices are produced. Voice therapy is the most effective treatment, but there is a lack of consensus for application of voice therapy. The purpose of this study was to examine the vocal characteristics of functional aphonia and the effect of voice therapy applied accordingly.Materials and Method From October 2019 to December 2020, 11 patients with functional aphonia were treated using voice therapy which was processing three stages such as vocal hygiene, trial therapy, and behavioral therapy. Of these, 7 patients who completed the voice evaluation before and after voice therapy was enrolled in this study. By retrospective chart review, clinical information such as sex, age, symptoms, duration, social and medical history, process of voice therapy, subjective and objective findings were analyzed. Voice parameters before and after voice therapy were compared.Results In GRBAS study, grade, rough, and asthenic, and in Consensus Auditory-Perceptual Evaluation of Voice, overall severity, roughness, pitch, and loudness were significantly improved after voice therapy. In Voice handicap index, all of the scores of total and sub-categories were significantly decreased. In objective voice analysis, jitter, cepstral peak prominence, and maximum phonation time were significantly improved.Conclusion The voice therapy was effective for the treatment of functional aphonia by restoring patient’s vocalization and improving voice quality, pitch and loudness.

Audio-Visual Interactions and the Influence of Colour on Noise Annoyance Evaluations

This study aims to examine the influence of colour exposure on noise annoyance. Previous studies in the literature have focused mostly on the effects of colour exposure on loudness judgements; however, due to the cognitive nature of multisensory perception, the influence of colour on noise annoyance also needs to be investigated. Our experiments were designed to administer non-information-carrying sound signals (i.e. white noise) and visual stimuli (i.e. abstract colour samples) and to limit visual and auditory contextual information. Participants were asked to evaluate noise annoyance on an 11-point International Commission on Biological Effects of Noise (ICBEN) scale. The experiments were conducted in the form of audio-visual tests. During these tests, random combinations of three white noise sound samples with sound pressure levels of 66 dB(A) (−4 dB[A] acoustic condition), 70 dB(A) (0 dB[A] acoustic condition) and 74 dB(A) (+4 dB[A] acoustic condition), and six visual stimuli, including the elementary colours of the Natural Colour System (NCS)—yellow (Y), red (R), blue (B), green (G), white (W) and black (S)—were presented to a total of 42 participants. The black colour sample was used to measure the audio-only control condition for the three white noise sound samples. The results of the study reveal that the effects of sound, the effects of colour and the interaction effects of colour and sound on perceived noise annoyance were statistically significant. The effects of colour on the loudness evaluations of the previous studies and the effects of colour on noise annoyance evaluations presented in this study show very similar and concordant results, indicating that the effects of colour on noise annoyance depend on the sound pressure level (SPL). The results indicate that the hue contrasts of red–green, red–blue and yellow–blue and the lightness contrast of yellow–blue influenced perceived noise annoyance when the SPL was low or high. Within the contrast pairs, red and yellow were perceived to be annoying, whereas blue and green were perceived to be non-annoying.

Combined effects of the thermal-acoustic environment on subjective evaluations in urban squares

Because human beings live in an environment in which various factors interact, it is necessary to study the effects of these factors on environmental evaluations. This study employs a questionnaire survey to explore the effects of the thermal-acoustic environment in urban squares on subjective evaluations (thermal evaluations, acoustic evaluations, and overall comfort) in severe cold regions. It also evaluates and predicts equivalent overall comfort under different conditions of the thermal-acoustic environment. The results indicate that with respect to thermal evaluations, a higher temperature causes a significant increase in thermal sensation in all the three seasons (summer, the transitional season, and winter) while traffic noise causes a slight increase in thermal sensation only in summer. Meanwhile, both temperature and traffic noise affect thermal comfort in all three seasons, with higher traffic noise causing lower thermal comfort. With respect to acoustic evaluations, higher traffic noise results in a more negative evaluation of subjective loudness and acoustic comfort, while the low temperature in winter and high temperature in summer increase acoustic discomfort. However, the interaction of temperature and traffic noise has an effect on acoustic comfort only in summer. In addition, temperature significantly affects overall comfort in all three seasons, while traffic noise has an effect only in the transitional season and summer; however, their interaction affects overall comfort only in winter.

Impacts of noise on staff cognitive performance in a hospital emergency department

The soundscape of a typical modern hospital emergency department is undoubtedly noisy. Noise-related stress can contribute to human error, adverse medication events, and physician burnout and may negatively affect physicians’ mental health and limit clinicians’ ability to provide high-quality patient care. Previous studies have revealed average sound pressure levels for hospitals worldwide to be in significant excess of the World Health Organization firm guidelines. However, neither sound pressure level measurements nor loudness evaluations provide enough insight into the problem or potential solutions. Noise sources in hospitals include monitor alarms, overhead paging, echogenic surfaces, trash bins, ring binders, and patient crying out, among others. These sounds can be abrupt, yet not sustained. In order to evaluate the impact of hospital staff distraction and propensity for human error due to noise, the authors have conducted research at a busy, urban emergency department. The effects of various sonic occurrences on the cognitive load and working memory of physicians operating in the emergency department were assessed using binaural augmented acoustic environments as the backdrop for cognitive executive function evaluations. This paper discusses the methods for the binaural augmentation, cognitive testing, and initial results and offers interpretation and potential solutions to address these results.

Loudness calculation procedure to study electronic steering column lock noise measurement

In the automotive field, the customer requirements for low interior noise and pleasant sound quality inside a vehicle are getting higher and higher. Various national and international regulatory authorities established and reviewed vehicle interior noise for the past years. Besides, lots of studies have shown that vehicle noise can influence the driver’s perceptions and also his or her driving capabilities. To succeed in this scenario, all manufacturers are investing in technology and research in order to improve their component performance. Working on the noise source so as to reduce the seriousness of these noise problems can be really effective. However, various engineering techniques are available to deal with noise and sound-measuring instruments, and systems can help to identify the nature of the problem and they can also be helpful in determining the right procedure to analyse the noise problem. This work proposes a procedure to evaluate the noise originated from an electronic steering column lock device which is used to lock and unlock the steering wheel according to European safety requirements. In particular, different standards and requirements for loudness evaluation have been discussed and the formulation of a straightforward procedure, which can be used to evaluate the loudness according to costumer’s requirements, is defined.

A Wireless Acoustic Array System for Binaural Loudness Evaluation in Cities

Networks of acoustic sensors are being deployed in smart cities to continuously monitor noise levels. In this paper, a novel acoustic sensor device is designed for binaural loudness evaluation, in a standalone platform. The audio is acquired from an array of microphones and a binaural signal is synthesized by a direction-of-arrival algorithm and a head-related transfer function. Hardware setup and software algorithms are presented and the results are discussed. Finally, the tests conducted in an early deployment show the feasibility of using the device to carry out large temporal and spatial sampling for the evaluation of binaural loudness.

Effect-for-cause inferencing in the evaluation of loudness among Toba Batak people

The paper presents evidence for an effect-for-cause inferencing process underlying the general style of using loud speech voice among Toba Batak speakers (Indonesia). A subjective reaction test was conducted to find out their perception towards the use of loud voice in three relational settings having different combinations of bipolarity: 1) vertical social distance and horizontal social distance; 2) vertical social distance only; and 3) horizontal social distance only. The results showed that in contexts where horizontal social distance remains, the absence of vertical distance significantly weakens the perception of impoliteness and unacceptability towards the use of loud voice. This indicates that Toba Bataks assume a pseudo social proximity when they are speaking to people with whom they have no horizontal social closeness. This method of inferencing is consistent with an effect-for-cause relational structure, being metonymic in nature.

Subjective evaluation of loudness and preference for noise containing audible tones

Noise in living environments often contains unwanted tonal components that contribute to the unpleasant and intrusive character of a sound and usually lead to an increased annoyance. In the measurement and assessment of noise immissions after the German DIN 45681:2005-3 standard, the higher annoyance due to audible tonal components is covered by so called tone adjustments. Depending on the SNR of a tonal component within each critical band, the level of a sound can be charged with a penalty of up to 6 dB. In this study, the psychoacoustic penalty levels for sounds containing tonal components are directly determined in listening tests. The points of subjective equality (PSEs) for loudness and preference are determined using a matching procedure. The level of the test sound with tonal components is varied until it is equally loud / preferred as a tone-free reference sound that is constant in level. The level difference between test and reference sound at the PSEs is a direct measure of the penalty level. In listening tests with pure multi-tone sounds the penalty levels were found to be well above 6 dB, indicating that for these stimuli the German DIN standard is underestimating the penalty level.

The Investigation of the Hall Loudness Evaluation

Loudness is one of the three basic parameters to assess the auditorium sound quality with reverberation time and balance together, it will be discussed in this paper. There are three expressions evaluating the loudness: listening level, the strength index and the mean forte sound pressure level of tutti-sound (LpF). Each of them has their merits and shortcomings. This paper will focus on these three expressions and the feasibility of checking and accepting acoustics of the hall by loudness.

Field study on the influence of spatial and environmental characteristics on the evaluation of subjective loudness and acoustic comfort in underground shopping streets

A large-scale measurement and subjective survey was undertaken in five underground shopping streets to determine the influence of spatial and environmental characteristics on users’ subjective loudness and acoustic comfort. The analysis on the spatial characteristics shows that the subjective loudness is higher in “street type” than in “square type” underground shopping streets when the equivalent continuous A-weighted sound pressure level (LAeq) is relatively high (75dBA). Acoustic comfort is higher in “square type” than in “street type” underground shopping streets where LAeq is relatively low (55dBA). Considering spatial functions, it is found that acoustic comfort is higher in a dining area than in a shopping area. In terms of environmental characteristics where air temperature, relative humidity, luminance and visual aspect were considered, the subjective loudness is influenced by humidity and luminance, with correlation coefficients of 0.10–0.30. The evaluation of acoustic comfort is influenced by air temperature, humidity, and luminance, with correlation coefficients of 0.10–0.40. There are significant correlations between the evaluation of environmental factors and subjective loudness, as well as, acoustic comfort. The correlation coefficients are 0.10–0.50. Moreover, respondents’ attitude to sound environment could influence their evaluation of subjective loudness and acoustic comfort.

Influence of Social and Behavioural Characteristics of Users on Their Evaluation of Subjective Loudness and Acoustic Comfort in Shopping Malls

A large-scale subjective survey was conducted in six shopping malls in Harbin City, China, to determine the influence of social and behavioural characteristics of users on their evaluation of subjective loudness and acoustic comfort. The analysis of social characteristics shows that evaluation of subjective loudness is influenced by income and occupation, with correlation coefficients or contingency coefficients of 0.10 to 0.40 (p<0.05 or p<0.01). Meanwhile, evaluation of acoustic comfort evaluation is influenced by income, education level, and occupation, with correlation coefficients or contingency coefficients of 0.10 to 0.60 (p<0.05 or p<0.01). The effect of gender and age on evaluation of subjective loudness and acoustic comfort is statistically insignificant. The effects of occupation are mainly caused by the differences in income and education level, in which the effects of income are greater than that of education level. In terms of behavioural characteristics, evaluation of subjective loudness is influenced by the reason for visit, frequency of visit, and length of stay, with correlation coefficients or contingency coefficients of 0.10 to 0.40 (p<0.05 or p<0.01). Evaluation of acoustic comfort is influenced by the reason for visit to the site, the frequency of visit, length of stay, and also season of visit, with correlation coefficients of 0.10 to 0.30 (p<0.05 or p<0.01). In particular, users who are waiting for someone show lower evaluation of acoustic comfort, whereas users who go to shopping malls more than once a month show higher evaluation of acoustic comfort. On the contrary, the influence of the period of visit and the accompanying persons are found insignificant.

Subjective evaluation of loudness of sonic booms indoors and outdoors

Subjective evaluation of loudness of sonic booms indoors and outdoors

Dependence of loudness evaluation by drivers on vehicle styling

Influence of participants' impressions of vehicle styling on loudness of acceleration sounds was investigated. A series of images of luxury and sporty vehicles were presented to the participants while acceleration sounds were being replayed. The results indicated that frequent drivers perceived that the sound associated with luxury vehicles was louder than that associated with sporty vehicles. On the other hand, infrequent drivers perceived almost no difference between the loudness of the two vehicle types. Then, the infrequent drivers underwent a pseudo-loudness evaluation test to increase amount of experience for listening vehicle sound with vehicle styling image. After the procedure, the influence of vehicle styling on loudness was investigated again for the infrequent drivers. The result showed that the influence for the infrequent drivers was quite different from that for the frequent drivers. The participants who rarely drove perceived that the sound associated with luxury vehicles was softer than that associated with sporty vehicles. Furthermore, a questionnaire was filled out by both groups to investigate their preferred vehicle characteristics such as exterior design and engine performance. As a result, loudness was clarified to depend on both the participants' impressions of vehicle styling and their preferred vehicle characteristics.

Effects of individual sound sources on the subjective loudness and acoustic comfort in underground shopping streets

Previous studies have demonstrated that human evaluation of subjective loudness and acoustic comfort depends on a series of factors in a particular situation rather than only on sound pressure levels. In the present study, a large-scale subjective survey has been undertaken on underground shopping streets in Harbin, China, to determine how individual sound sources influence subjective loudness and acoustic comfort evaluation. Based on the analysis of case study results, it has been shown that all individual sound sources can increase subjective loudness to a certain degree. However, their levels of influence on acoustic comfort are different. Background music and the public address system can increase acoustic comfort, with a mean difference of 0.18 to 0.32 and 0.21 to 0.27, respectively, where a five-point bipolar category scale is used. Music from shops and vendor shouts can decrease acoustic comfort, with a mean difference of −0.11 to −0.38 and −0.39 to −0.62, respectively. The feasibility of improving acoustic comfort by changing certain sound sources is thus demonstrated.