Perceived Loudness and Visually-Determined Auditory Distance

Perception ◽  
1981 ◽  
Vol 10 (5) ◽  
pp. 531-543 ◽  
Author(s):  
Donald H Mershon ◽  
Douglas H Desaulniers ◽  
Stephan A Kiefer ◽  
Thomas L Amerson ◽  
Jeanne T Mills
Keyword(s):  
Apparent Distance ◽  
Source Location ◽  
Sound Level ◽  
Visual Capture ◽  
Noise Stimulus ◽  
Auditory Distance ◽  
Sound Levels ◽  
Apparent Source ◽  
True Source ◽  
Physical Changes

Three experiments were conducted to determine whether variations in the perceived distance to a test sound could influence its loudness in the absence of physical changes in sound-level. The phenomenon of visual capture provided the means for manipulating apparent distance. A ‘dummy’ loudspeaker was used to vary the apparent source location of a short noise stimulus while the true source of this sound remained fixed (and hidden) with respect to the observer. Sound-levels from 40 to 75 dB(A) were presented to independent groups of observers in either anechoic or semi-reverberant acoustical environments. In general, reported loudness increased with perceived distance. This finding has implications for conceptualizing the phenomenon of loudness constancy.

scholarly journals The Spatial Selective Auditory Attention of Cochlear Implant Users in Different Conversational Sound Levels

2021 ◽  
Vol 10 (14) ◽  
pp. 3078
Author(s):  
Sara Akbarzadeh ◽  
Sungmin Lee ◽  
Chin-Tuan Tan
Keyword(s):  
Cochlear Implant ◽  
Sound Level ◽  
Auditory Attention ◽  
Impaired Hearing ◽  
Speech Stimuli ◽  
Electric Hearing ◽  
Sound Levels ◽  
Acoustic Hearing ◽  
Speech Envelope ◽  
Different Levels

In multi-speaker environments, cochlear implant (CI) users may attend to a target sound source in a different manner from normal hearing (NH) individuals during a conversation. This study attempted to investigate the effect of conversational sound levels on the mechanisms adopted by CI and NH listeners in selective auditory attention and how it affects their daily conversation. Nine CI users (five bilateral, three unilateral, and one bimodal) and eight NH listeners participated in this study. The behavioral speech recognition scores were collected using a matrix sentences test, and neural tracking to speech envelope was recorded using electroencephalography (EEG). Speech stimuli were presented at three different levels (75, 65, and 55 dB SPL) in the presence of two maskers from three spatially separated speakers. Different combinations of assisted/impaired hearing modes were evaluated for CI users, and the outcomes were analyzed in three categories: electric hearing only, acoustic hearing only, and electric + acoustic hearing. Our results showed that increasing the conversational sound level degraded the selective auditory attention in electrical hearing. On the other hand, increasing the sound level improved the selective auditory attention for the acoustic hearing group. In the NH listeners, however, increasing the sound level did not cause a significant change in the auditory attention. Our result implies that the effect of the sound level on selective auditory attention varies depending on the hearing modes, and the loudness control is necessary for the ease of attending to the conversation by CI users.

scholarly journals Impact of sound levels and patient-related factors on sleep of patients in the intensive care unit: a cross-sectional cohort study

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Piotr F. Czempik ◽  
Agnieszka Jarosińska ◽  
Krystyna Machlowska ◽  
Michał P. Pluta
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Sleep Quality ◽  
Sleep Duration ◽  
Smartphone Application ◽  
Sound Level ◽  
Related Factors ◽  
Cross Sectional ◽  
Sound Levels ◽  
The Impact

Abstract Sleep disruption is common in patients in the intensive care unit (ICU). The aim of the study was to measure sound levels during sleep-protected time in the ICU, determine sources of sound, assess the impact of sound levels and patient-related factors on duration and quality of patients' sleep. The study was performed between 2018 and 2019. A commercially available smartphone application was used to measure ambient sound levels. Sleep duration was measured using the Patient's Sleep Behaviour Observational Tool. Sleep quality was assessed using the Richards-Campbell Sleep Questionnaire (RCSQ). The study population comprised 18 (58%) men and 13 (42%) women. There were numerous sources of sound. The median duration of sleep was 5 (IQR 3.5–5.7) hours. The median score on the RCSQ was 49 (IQR 28–71) out of 100 points. Sound levels were negatively correlated with sleep duration. The cut-off peak sound level, above which sleep duration was shorter than mean sleep duration in the cohort, was 57.9 dB. Simple smartphone applications can be useful to estimate sound levels in the ICU. There are numerous sources of sound in the ICU. Individual units should identify and eliminate their own sources of sound. Sources of sound producing peak sound levels above 57.9 dB may lead to shorter sleep and should be eliminated from the ICU environment. The sound levels had no effect on sleep quality.

Incubator Noise

PEDIATRICS ◽  
1975 ◽  
Vol 56 (4) ◽  
pp. 617-617
Author(s):  
Gōsta Blennow ◽  
Nils W. Svenningsen ◽  
Bengt Almquist
Keyword(s):  
Low Frequency ◽  
Sound Level ◽  
Noise Levels ◽  
Frequency Sound ◽  
Mechanical Noise ◽  
Sound Levels ◽  
Infant Incubator ◽  
Improved Model ◽  
Model C

Recently we reported results from studies of incubator noise levels.1 It was found that in certain types of incubators the noise was considerable, and attention was called to the sound level in the construction of new incubators. Recently we had the opportunity to study an improved model of Isolette Infant Incubator Model C-86 where the mechanical noise from the electrically powered motor has been partially eliminated. With this modification it has been possible to lower the low-frequency sound levels to a certain degree in comparison to the levels registered in our study.

scholarly journals L-type calcium channels refine the neural population code of sound level

2016 ◽  
Vol 116 (6) ◽  
pp. 2550-2563 ◽  
Author(s):  
Calum Alex Grimsley ◽  
David Brian Green ◽  
Shobhana Sivaramakrishnan
Keyword(s):  
Calcium Channels ◽  
Calcium Current ◽  
Dynamic Range ◽  
Sound Level ◽  
Neural Population ◽  
Total Calcium ◽  
Local Networks ◽  
Sound Levels ◽  
Local Circuits

The coding of sound level by ensembles of neurons improves the accuracy with which listeners identify how loud a sound is. In the auditory system, the rate at which neurons fire in response to changes in sound level is shaped by local networks. Voltage-gated conductances alter local output by regulating neuronal firing, but their role in modulating responses to sound level is unclear. We tested the effects of L-type calcium channels (CaL: CaV1.1–1.4) on sound-level coding in the central nucleus of the inferior colliculus (ICC) in the auditory midbrain. We characterized the contribution of CaL to the total calcium current in brain slices and then examined its effects on rate-level functions (RLFs) in vivo using single-unit recordings in awake mice. CaL is a high-threshold current and comprises ∼50% of the total calcium current in ICC neurons. In vivo, CaL activates at sound levels that evoke high firing rates. In RLFs that increase monotonically with sound level, CaL boosts spike rates at high sound levels and increases the maximum firing rate achieved. In different populations of RLFs that change nonmonotonically with sound level, CaL either suppresses or enhances firing at sound levels that evoke maximum firing. CaL multiplies the gain of monotonic RLFs with dynamic range and divides the gain of nonmonotonic RLFs with the width of the RLF. These results suggest that a single broad class of calcium channels activates enhancing and suppressing local circuits to regulate the sensitivity of neuronal populations to sound level.

Elevated Sound Levels within a Busy NICU

2005 ◽  
Vol 24 (6) ◽  
pp. 33-37 ◽  
Author(s):  
Charlene Krueger ◽  
Susan Wall ◽  
Leslie Parker ◽  
Rose Nealis
Keyword(s):  
Preterm Infants ◽  
Noise Level ◽  
Sound Level ◽  
Behavioral Effects ◽  
Outcome Variable ◽  
Sound Levels ◽  
Main Outcome Variable

Purpose: Elevated sound levels in the NICU may contribute to undesirable physiologic and behavioral effects in preterm infants. This study describes sound levels in a busy NICU in the southeastern U.S. and compares the findings with recommended NICU noise level standards.Design: NICU sound levels were recorded continuously at nine different locations within the NICU. Hourly measurements of loudness equivalent (Leq) sound level, sound level exceeded 10 percent of the time (L10), and maximum sound level (Lmax) were determined.Sample: Sound levels were sampled from nine different locations within the NICU.Main Outcome Variable: Sound levels are described using the hourly, A-weighted Leq, L10, and Lmax.Results: The overall average hourly Leq (M = 60.44 dB, range = 55–68 dB), L10 (M = 59.26 dB, range = 55–66 dB), and Lmax (M = 78.39, range = 69–93 dB) were often above the recommended sound levels (hourly Leq <50 dB, L10 <55 dB, and 1-second Lmax <70 dB). In addition, certain times of day, such as 6–7 AM and 10 AM–12 noon, were noisier than other times of day.

scholarly journals INFRASOUND AND LOW FREQUENCY NOISE IMMISION FROM PIPELINES. iMPROVING THE ISO 1996-2:2017 PROPOSED METHODS. CASES STUDIES CONDUCTED AT LOS ANDES AND PERUVIAN RAINFOREST

Akustika ◽  
2019 ◽  
Vol 32 ◽  
pp. 335-345
Author(s):  
Walter Montano
Keyword(s):  
Low Frequency ◽  
Sound Level ◽  
Frequency Noise ◽  
Gas Extraction ◽  
Howler Monkeys ◽  
Noise Sources ◽  
Industrial Facilities ◽  
Sound Levels ◽  
Continuous Noise ◽  
Amazonian Rainforest

The gas extraction wells are in Amazonian rainforest and by them there are their industrial facilities. The pipeline has about 800 km with four pumps stations and two compressor stations. The challenge of conducting sound measurements was important-there is no specialized literature-and other noise "sources" are howler monkeys, cicadidae chirping, woodpeckers, trees´foliage, etc. However the problem is simply because those fixed industrial facilities are the only ones. People live in isolated hamlet on the side of dirt roads, so they are exposed 24/7 to the continuous noise; at homes 4 km away from the plants the sound level is 60 dBC, but in the spectrum of ILFN tones could not be identified. This Paper presents the procedures that were developed to identify the ILFN tones, improving the methods proposed in ISO 1996-2, writing a software that "automatically eliminates" the sound levels that don´t belong to the industry,

Coregulation in Salivary Cortisol During Maternal Holding of Premature Infants

2008 ◽  
Vol 10 (3) ◽  
pp. 226-240 ◽  
Author(s):  
Madalynn Neu ◽  
Mark L. Laudenslager ◽  
JoAnn Robinson
Keyword(s):  
Salivary Cortisol ◽  
Neonatal Intensive Care ◽  
Sound Level ◽  
Holding Time ◽  
Sound Levels ◽  
Ambient Sound ◽  
Antenatal Steroids ◽  
Postconceptional Age ◽  
Research Questions ◽  
Cortisol Levels

Purpose: The purpose of this study was to examine coregulation between mothers and preterm infants in hypothalamic-pituitary-adrenocortical (HPA) system activity, as indicated by salivary cortisol levels, while mothers held their infants. The research questions were (a) does mother—infant coregulation in HPA activity occur during holding? and (b) if mother— infant coregulation in HPA activity exists during holding, do type of holding, antenatal steroids, sound level, and maternal touch influence this coregulation? Sample: The sample consisted of 20 mother— infant dyads with infants at a mean postconceptional age of 34.7 weeks (+0.7) and average postnatal age of 15 days (+9) at the time of cortisol sampling. Design: The design was exploratory using convenience sampling. Maternal and infant cortisol levels were obtained at Time 1 (baseline) and Time 2 (end of holding); at each time, the absolute differences in levels between mother and infant were determined. Coregulation was operationalized as less difference between maternal-infant cortisol levels immediately after holding (Time 2) as compared to before holding (Time 1). Results: The two variables with the highest correlation with the Time 1/Time 2 difference score included antenatal steroids and ambient sound level, which were entered into a linear regression equation as predictor variables. A coregulatory relationship in cortisol levels existed between mothers and infants during holding, which was moderated by sound levels. Nurses in the neonatal intensive care unit (NICU) can facilitate the mother—infant relationship, as reflected in coregulatory measures, by promoting a quiet environment, particularly around mothers who are holding their infants.

scholarly journals Appraisal of Noise Level Dissemination Surrounding Mining and Industrial Areas of Keonjhar, Odisha: a Comprehensive Approach Using Noise Mapping

2017 ◽  
Vol 42 (3) ◽  
pp. 423-432 ◽  
Author(s):  
Satish K. Lokhande ◽  
Satyajeet A. Dhawale ◽  
Samir S. Pathak ◽  
Rakesh Gautam ◽  
Mohindra C. Jain ◽  
...  
Keyword(s):  
Noise Level ◽  
Sound Level ◽  
Noise Levels ◽  
Night Time ◽  
Noise Mapping ◽  
High Noise ◽  
Sensitive Areas ◽  
Sound Levels ◽  
Directorate General ◽  
Open Cast

Abstract Noise mapping is a well-established practice among the European nations, and it has been follow for almost two decades. Recently, as per guidelines of the Directorate General of Mines Safety (DGMS), India, noise mapping has been made mandatory in the mining expanses. This study is an effort to map the noise levels in nearby areas of mines in the northern Keonjhar district. The motive of this study is to quantify the existing A-weighted time-average sound level (LAeq,T ) in the study area to probe its effects on the human dwellings and noise sensitive areas with the probability of future development of the mines, roads, and industrial and commercial zone. The LAeq,T was measured at 39 identified locations, including industrial, commercial, residential, and sensitive zones, 15 open cast mines, 3 major highways, and 3 haulage roads. With the utilisation of Predictor LimA Software and other GIS tools, the worked out data is mapped and noise contours are developed for the visualisation and identification of the extent and distribution of sound levels across the study area. This investigation discloses that the present noise level at 60% of the locations in silence and residential zone exposed to significantly high noise levels surpasses the prescribed limit of Central Pollution Control Board (CPCB), India. The observed day and night time LAeq, T level of both zones ranged between 43.2-62.2 dB(A) and 30.5-53.4 dB(A), respectively, whereas, the average Ldn values vary between 32.7 and 51.2 dB(A). The extensive mobility of heavy vehicles adjoining the sensitive areas and a nearby plethora of open cast mines is the leading cause of exceeded noise levels. The study divulges that the delicate establishments like schools and hospitals are susceptible to high noise levels throughout the day and night. A correlation between observed and software predicted values gives R2 of 0.605 for Ld, 0.217 for Ln, and 0.524 for Ldn. Finally, the mitigation measure is proposed and demonstrated using a contour map showing a significant reduction in the noise levels by 0-5.3 dB(A).

scholarly journals Influence of the Acoustic Cover of the Modular Expansion Joint on the Acoustic Climate in the Bridge Structure Surroundings

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2842
Author(s):  
Janusz Bohatkiewicz ◽  
Michał Jukowski ◽  
Maciej Hałucha ◽  
Marcin Dębiński
Keyword(s):  
Sound Level ◽  
Structural Elements ◽  
Expansion Joint ◽  
Expansion Joints ◽  
The Road ◽  
Sound Levels ◽  
Road Surfaces ◽  
Before And After ◽  
Bridge Structures

The noise generated at the interface between the wheels of vehicles and the road surface is well recognized in the literature worldwide. Many publications describe the phenomenon of reducing this kind of impact by silent road surfaces. A specific type of this noise is the sound generated by vehicles passing over the expansion joints of bridge structures. Due to the impulsive nature of this sound, it is very onerous for people living in the close vicinity of bridge structures. The passage of vehicles over expansion joints causes the formation of vibrations that are transmitted to the structural elements of bridge structures, which may cause the formation of the material sounds (especially arduous in the case of bridges with steel elements). An attempt to reduce this impact was made by making a prototype acoustic cover of the expansion joint on the selected bridge. The paper presents the results of research on the “in situ” acoustic effectiveness of this cover. Additionally, the noise was modelled in the object surroundings before and after the cover’s application. The acoustic efficiency of the cover in the whole measured frequency range was 5.3 dBA. In the narrower frequency bands (1/3 octave bands), larger sound level reductions were observed. The maximum sound levels measured under the tested dilatation were less than 10.0 dBA lower than the maximum sound levels measured under the reference dilatation.

Response of clupeid fish to ultrasound: a review

2004 ◽  
Vol 61 (7) ◽  
pp. 1057-1061 ◽  
Author(s):  
Arthur N. Popper ◽  
Dennis T.T. Plachta ◽  
David A. Mann ◽  
Dennis Higgs
Keyword(s):  
Inner Ear ◽  
Sensory Epithelium ◽  
Sound Level ◽  
Behavioural Response ◽  
American Shad ◽  
Low Intensity ◽  
Blueback Herring ◽  
Sound Levels ◽  
Directional Movement ◽  
Anatomical Evidence

Abstract A number of species of clupeid fish, including blueback herring, American shad, and gulf menhaden, can detect and respond to ultrasonic sounds up to at least 180 kHz, whereas other clupeids, including bay anchovies and Spanish sardines, do not appear to detect sounds above about 4 kHz. Although the location for ultrasound detection has not been proven conclusively, there is a growing body of physiological, developmental, and anatomical evidence suggesting that one end organ of the inner ear, the utricle, is likely to be the detector. The utricle is a region of the inner ear that is very similar in all vertebrates studied to date, except for clupeid fish, where it is highly specialized. Behavioural studies of the responses of American shad to ultrasound demonstrate that they show a graded series of responses depending on the sound level and, to a lesser degree, on the frequency of the stimulus. Low-intensity stimuli elicit a non-directional movement of the fish, whereas somewhat higher sound levels elicit a directional movement away from the sound source. Still higher level sounds produce a “wild” chaotic movement of the fish. These responses do not occur until shad have developed the adult utricle that has a three-part sensory epithelium. We speculate that the response of the American shad (and, presumably, other clupeids that can detect ultrasound) to ultrasound evolved to help these species detect and avoid a major predator – echolocating cetaceans. As dolphins echolocate, the fish are able to hear the sound at over 100 m. If the dolphins detect the fish and come closer, the nature of the behavioural response of the fish changes in order to exploit different avoidance strategies and lower the chance of being eaten by the predators.

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