Fetal Music Perception: The Role of Sound Transmission

1998 ◽  
Vol 15 (3) ◽  
pp. 307-317 ◽  
Author(s):  
R. M. Abrams ◽  
S. K. Griffiths ◽  
X. Huang ◽  
J. Sain ◽  
G. Langford ◽  
...  
Keyword(s):  
High Frequency ◽  
Music Perception ◽  
Sound Pressure ◽  
Pressure Level ◽  
Spectral Features ◽  
Fetal Sheep ◽  
Marked Diminution ◽  
Sound Environment ◽  
Musical Sounds

The fetal sound environment is now known to be rich and varied. Playback of tapes made from intrauterine recordings of sounds reveals some muffling, suggesting an attenuation of high-frequency sounds at the surface of the abdominal wall and during transmission through abdominal and uterine tissues and fluids. The present experiments show how the spectral features of synthesized musical sounds are altered once they reach the ear of the fetal sheep. Below 300 Hz, intrauterine sound pressure levels are nearly identical to those recorded outside the ewe. Between 315 and 2500 Hz, the attenuation increases at a rate of 5 dB per octave. Spectral analyses of trumpet and flugelhorn sounds recorded in utero show a marked diminution in sound pressure level in partials above 600 Hz; this diminution could be perceived by the fetus as an altered timbre.

Just noticeable difference of sound pressure level of speech in open-plan office

2021 ◽  
Vol 263 (1) ◽  
pp. 5166-5169
Author(s):  
Haram Lee ◽  
Hyunin Jo ◽  
Jin Yong Jeon
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Paired Comparison ◽  
Subjective Evaluation ◽  
Simulation Models ◽  
Pressure Level ◽  
Just Noticeable Difference ◽  
Sound Sources ◽  
Sound Environment ◽  
Open Plan

In this study, the general sound environment characteristics of open-plan office (OPO) were investigated, and just noticeable difference (JND) of sound pressure level of speech at a distance of 4 m (Lp,A,S,4m) suggested in ISO 3382-3 was suggested. First, in order to understand the sound environment characteristics of OPO, one minute sound sources recorded in 8 offices were collected and physical and psychological acoustic characteristics were analyzed. A total of 30 office workers were subject to subjective evaluation on 8 sound sources, and they were asked to respond to questionnaires related to annoyance, work satisfaction, and speech privacy. Next, to investigate the JND, two computer simulation models identical to those of the actual OPO were implemented, and sound sources each having six different Lp,A,S,4m values were generated through the change of the sound absorption coefficient of the interior finish. The JND of Lp,A,S,4m was presented by performing paired comparison for the same subjects. It is expected that the JND of Lp,A,S,4m proposed in this study can be used for the sound environment rating of OPO.

Binaural interaction in high-frequency neurons in inferior colliculus of the cat: effects of variations in sound pressure level on sensitivity to interaural intensity differences

1990 ◽  
Vol 63 (3) ◽  
pp. 570-591 ◽  
Author(s):  
D. R. Irvine ◽  
G. Gago
Keyword(s):  
Inferior Colliculus ◽  
Sound Pressure Level ◽  
High Frequency ◽  
Sound Pressure ◽  
Pressure Level ◽  
Central Nucleus ◽  
Sensitivity Functions ◽  
Rate Intensity ◽  
Ipsilateral Stimulation ◽  
Intensity Functions

1. Development of models of the manner in which interaural intensity differences (IIDs), the major binaural cue for the azimuthal location of high-frequency sounds, are coded by populations of neurons requires knowledge of the extent to which the IID sensitivity of individual neurons is invariant with changes in sound pressure level (SPL) and other stimulus parameters. To examine this tissue, recordings were obtained from a large sample (n = 458) of neurons with characteristic frequency (CF) greater than 3 kHz in the central nucleus of the inferior colliculus (ICC) of anesthetized cats. The sensitivity to IIDs and the effects of changes in SPL on this sensitivity were examined in neurons receiving excitatory contralateral input and inhibitory or mixed inhibitory/facilitatory ipsilateral input (EI neurons). 2. The form of an EI neuron's IID sensitivity and the effects of changes in SPL on that sensitivity were found to be determined in part by the characteristics of the neuron's rate-intensity function for monaural contralateral stimulation, and detailed rate-intensity functions were therefore obtained for 91 neurons. Many ICC neurons have nonmonotonic rate-intensity functions, the proportion so classified depending on the criterion of nonmonotonicity employed. 3. IID sensitivity functions for CF tonal stimuli were obtained at one or more intensities for 90 neurons, using a method of generating IIDs that kept the average binaural intensity (ABI) of the stimuli at the two ears constant. In the standard ABI range in which a function was obtained for each unit, the majority of EI neurons (72%) had monotonic (sigmoidal) or near-monotonic IID sensitivity functions. The remainder had nonmonotonic (peaked) IID sensitivity functions, which were attributable either to mixed inhibitory and facilitatory ipsilateral influences or to the fact that the effects of ipsilateral stimulation were superimposed on nonmonotonic effects of changes in intensity at the excitatory ear. 4. IID sensitivity was examined at two or more ABIs (3-5 in most cases) for 40 neurons classified as having monotonic or near-monotonic functions in the standard ABI range and for 7 neurons classified as nonmonotonic. For a small proportion of neurons with monotonic IID sensitivity functions, the form of the function was relatively invariant with changes in ABI. In those monotonic neurons in which the form of the IID sensitivity function varied with changes in ABI, the most common type of variation was that the position of the sloping portion of the function shifted systematically in the direction of larger IIDs favoring the ipsilateral ear as ABI increased.(ABSTRACT TRUNCATED AT 400 WORDS)

Consistency of Electroacoustic Characteristics Across Components of FM Systems

1991 ◽  
Vol 34 (3) ◽  
pp. 628-635 ◽  
Author(s):  
Linda M. Thibodeau ◽  
Kathryn A. Saucedo
Keyword(s):  
Sound Pressure Level ◽  
High Frequency ◽  
Sound Pressure ◽  
Pressure Level ◽  
Input Noise ◽  
The Individual ◽  
Equivalent Input Noise

In the absence of national or international electroacoustic standards for the evaluation of Frequency Modulated (FM) amplification systems, it becomes important to know the variability one may expect across similar models. Evaluation of thirty FM systems of the same model obtained from three different educational sites was performed to determine the variability that may occur as a result of the receiver, lapel microphone, or neckloop. There was a range as great as 20 dB in high frequency average saturation sound pressure level and equivalent input noise across receivers, lapel microphones, and neckloops. These results highlight the need for regular electroacoustic monitoring of not only the FM transmitter and receiver, but also the individual components, such as the lapel microphone and the neckloop.

The Study on Influence of High Frequency Noise on Sound Quality for Generator

2011 ◽  
Vol 105-107 ◽  
pp. 74-79
Author(s):  
Zha Gen Ma ◽  
Xue Ying Xu ◽  
Guo Hua Han
Keyword(s):  
Sound Pressure Level ◽  
High Frequency ◽  
Sound Pressure ◽  
Evaluation Method ◽  
Subjective Evaluation ◽  
Internal Noise ◽  
Sound Quality ◽  
Pressure Level ◽  
Frequency Noise ◽  
High Frequency Noise

As cars become quieter the sound quality of components becomes more critical in the customer perception of car quality. This requires a need of new evaluation method for the specification of component sounds. Considering that high frequency noise plays an important roll for internal noise, the noise signals in the range from 7000Hz to 8000Hz are specially emphasized. Then the acoustic evaluation parameters, such as Sound Pressure Level, Sharpness and Steadiness have been evaluated. Judged from experiences and measuring results, an abnormal noise comes from Generator, through the exchange of Generator, Sound Pressure Level and sharpness were greatly improved. At the same time, subjective evaluation also indicated that there was no complaint any more in passenger compartment. Low Sound Pressure Level, sharpness can lead to perceived high product quality.

Test and Analysis of Noise Reduction Effect for Different Heights and Distances of Sound Barrier

2011 ◽  
Vol 243-249 ◽  
pp. 4447-4450 ◽  
Author(s):  
Yan Liu ◽  
Bing Yang ◽  
Xiao Pai Zhang ◽  
Zhi Fang Zhong ◽  
Hua Xin Dong ◽  
...  
Keyword(s):  
Noise Reduction ◽  
Sound Pressure Level ◽  
High Frequency ◽  
Sound Pressure ◽  
Pressure Level ◽  
High Frequency Range ◽  
Frequency Range ◽  
Sound Barrier ◽  
Test Points ◽  
Reduction Effect

Based on the comparative analysis on the low-noise road surface, noise reduction green belts, noise barriers and other noise reduction methods, the sound barrier is put forward as an important method for reducing the city road traffic noise. The noise reduction effects for different heights and different distances of the sound barrier are tested and analyzed through noise and vibration test and analysis system, the following conclusions can be drawn. At the same heights from the ground, the father the test points away from the noise barrier, the higher the sound pressure level will be; At the same distances from the sound barrier, the nearer the test points from the ground, the smaller the sound pressure level will be; All of the sound pressure level curves have basically the same variation trend and the main noise frequency band is from 160 to 1600Hz; In the high frequency range which is greater than 1600Hz, the sound pressure level decrease significantly, indicating that the sound barrier has better noise reduction effect for high frequency range. The results provide the basis for the design of the sound barriers.

Prediction and analysis of sound field in long enclosures with a modal-based method

2021 ◽  
Vol 69 (6) ◽  
pp. 518-529
Author(s):  
Changyong Jiang ◽  
Xiang Liu ◽  
Stephany Y. Xu ◽  
Shangyu Zhang
Keyword(s):  
Porous Material ◽  
Point Source ◽  
Sound Pressure Level ◽  
High Frequency ◽  
Sound Pressure ◽  
Prediction Method ◽  
Sound Field ◽  
Pressure Level ◽  
Noise Levels ◽  
Level Reduction

In this paper, the efficacy of porous ceiling treatment to reduce noise levels inside a typical tunnel is examined with a validated modal-based prediction method. It is found that, for a point source, the effect of increasing porous ceiling thickness on sound pressure level (SPL) attenuation along the tunnel is limited. A porous ceiling with thickness of 0.3 m is comparable with an infinite porous ceiling in middle and high frequency ranges. For a line source, the effect of ceiling thickness on SPL reduc- tion in this typical tunnel is limited. Sound pressure level reduction of 4 dBA is real- ized with 0.3 m porous ceiling, which is the same as infinite ceiling and only 1 dBA smaller than the theoretically optimized value. These results suggest that, in the event only ceiling treatment is considered, 0.3 m porous material is sufficient for noise re- duction in this typical tunnel.

scholarly journals Effects of openings on the wind–sound environment in the traditional residential streets in a severe cold city of China

2018 ◽  
Vol 47 (5) ◽  
pp. 808-825 ◽  
Author(s):  
Yumeng Jin ◽  
Hong Jin ◽  
Jian Kang ◽  
Ziyue Yu
Keyword(s):  
Wind Velocity ◽  
Sound Pressure Level ◽  
Physical Environment ◽  
Sound Pressure ◽  
Field Measurements ◽  
Pressure Level ◽  
Optimized Design ◽  
Residential Areas ◽  
Sound Environment ◽  
The Difference

The streets in the traditional residential areas of severe cold cities in China often have openings leading to enclosed courtyards. These openings connect the street to the courtyard space, which affects the physical environment of the residential streets. This paper uses field measurements and numerical simulation to study the wind–sound environment in the street, comparing and analysing the effects of the existence, size and form of openings on the wind–sound environment in the street. The results indicate that both the average wind velocity and sound pressure level have some degree of reduction around the opening, with the difference of wind velocity reaching 1.0 m/s and the difference in sound pressure level reaching 0.5–1.6 dB. Additionally, the T30 changes from 0.2 s to 0.4 s around the opening, while the average T30 in the street also varies. Increasing the width of the opening by 1 m increases the influential range of the opening on the sound environment by 0.5–4 m. In contrast, the width of the opening has little effect on the sound pressure level and the T30. Compared with an entrance of the same width, a gap intensifies the fluctuation of the local wind velocity and causes the average T30 to reduce by 0.3 s. The results of this paper lay a data foundation for further studies on the optimized design of the physical environment in enclosed residential areas.

Audiological and noise exposure findings among members of a brazilian folklore music group

Work ◽  
2021 ◽  
pp. 1-7
Author(s):  
Carina Moreno Dias Carneiro Muniz ◽  
Sergio Fernando Saraiva da Silva ◽  
Rachel Costa Façanha ◽  
Daniela Bassi-Dibai ◽  
Fabricio Brito Silva ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Sound Pressure Level ◽  
High Frequency ◽  
Sound Pressure ◽  
Noise Exposure ◽  
Descriptive Study ◽  
Pressure Level ◽  
Noise Induced Hearing Loss ◽  
Loud Noise ◽  
Two Stages

BACKGROUND: Musicians and dancers can be considered an at-risk population for developing noise-induced hearing loss. OBJECTIVES: To determine the audiological profile of members of a folklore-related music group and quantify noise exposure at their rehearsal venue. METHODS: This was a quantitative and descriptive study. The musicians and dancers were evaluated in two stages: an interview about their working life, followed by high frequency tonal audiometry. The sound pressure level in the group’s rehearsal venue was measured using a BEK 2270 Noise Analyzer. RESULTS: A total of 7.2% of the subjects had noise-induced hearing loss (NIHL) and 39% of the audiometric tests were notch type. During the interview 31.7% of the subjects mentioned discomfort from loud noise, although none of them used ear protection. The environmental assessment showed inadequate humidity and oscillating temperature. Twenty sound pressure level measurements were performed for Leq (equivalent sound pressure levels) and the results ranged from 88 dB (A) to 99 dB (A) with a mean of 97.05. CONCLUSIONS: Exposure to high levels of sound pressure has led to NIHL in some members of the group. Some of those with normal hearing also presented a notch configuration characteristic of NIHL. Tinnitus, indicating that a change in hearing has occurred, was the most frequent auditory symptom.

scholarly journals Analysing Sound Environment and Architectural Characteristics of Libraries through Indoor Soundscape Framework

2016 ◽  
Vol 41 (2) ◽  
pp. 203-212 ◽  
Author(s):  
Papatya Nur Dokmeci Yorukoglu ◽  
Jian Kang
Keyword(s):  
Sound Pressure ◽  
Pressure Level ◽  
Room Acoustics ◽  
Control Engineering ◽  
Architectural Analysis ◽  
Architectural Element ◽  
Sound Environment ◽  
Overall Evaluation ◽  
Spatial Referencing ◽  
Architectural Characteristics

Abstract This study presents the indoor soundscape framework in detail by describing the variables and factors that form an indoor soundscape study. The main objective is to introduce a new indoor soundscaping framework and systematically explain the variables that contribute to the overall evaluation of an indoor soundscape. Hence, the dependencies of physical and psychoacoustical factors of the sound environment and the spatial factors of the built entity are statistically tested. The new indoor soundscaping framework leads to an overarching evaluation perspective of enclosed sound environments, combining objective room acoustics research and noise control engineering with architectural analysis. Therefore, it is hypothesised that case spaces with certain plan organisations, volumetric relations, and spatial referencing lead to differentiated sound pressure level (SPL) and loudness (N) values. SPL and N parametric variances of the sound environments are discussed through the statistical findings with respect to the architectural characteristics of each library case space. The results show that the relation between crowd level variances and sound environment parametric values is statistically significant. It is also found that increasing the atrium height and atrium void volume, the atrium’s presence as a common architectural element, and its interpenetrating reference and domain containment results in unwanted variances and acoustic formations, leading to high SPL and N values.

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