scholarly journals A laboratory study for occupational safety and health on the structure of airborne ultrasound fields

Acta Acustica ◽  
2020 ◽  
Vol 4 (4) ◽  
pp. 12
Author(s):  
Robert Schöneweiß ◽  
Christoph Kling ◽  
Christian Koch
Keyword(s):  
Laboratory Study ◽  
Occupational Safety ◽  
Sound Pressure ◽  
Structural Characteristics ◽  
Three Dimensional ◽  
Measurement Procedure ◽  
Measuring System ◽  
Public And Private ◽  
Sound Pressure Levels ◽  
Airborne Ultrasound

While exposure to airborne ultrasound is increasing in occupational contexts and in public and private spaces, existing demand for reliable and traceable determination of exposure to sound with frequencies above 16 kHz cannot currently be satisfied due to a lack of adequate measurement devices and procedures adapted to the specifics of airborne ultrasound. So that this study may serve as a first step for the development of a novel measurement procedure, its aim is to create a comprehensive database of the structures of airborne ultrasound fields present in occupational contexts. Based on this, the limitations of measurement procedures commonly used in the audible frequency range are clarified and the structural characteristics of airborne ultrasound fields investigated. This paper presents a laboratory study of the structure of the airborne ultrasound field of an ultrasonic welding machine, which can be considered a representative occupational source of airborne ultrasound. For this study, the technical and procedural requirements of a measuring system are derived and used to set up and calibrate a measuring system for three-dimensional, high spatial resolution scans of sound pressure levels in the laboratory. The measurement results reveal complex, extensive and very fine-structured interference patterns, some of which have sound pressure levels of up to 138 dB (re 20 μPa).

Real Ear Sound Pressure Levels Developed by Three Portable Stereo System Earphones

1992 ◽  
Vol 1 (4) ◽  
pp. 52-55 ◽  
Author(s):  
Gail L. MacLean ◽  
Andrew Stuart ◽  
Robert Stenstrom
Keyword(s):  
High Frequency ◽  
Sound Pressure ◽  
Low Frequency ◽  
Test System ◽  
Output Frequency ◽  
Frequency Effects ◽  
Adult Men ◽  
Frequency Responses ◽  
Significant Difference ◽  
Sound Pressure Levels

Differences in real ear sound pressure levels (SPLs) with three portable stereo system (PSS) earphones (supraaural [Sony Model MDR-44], semiaural [Sony Model MDR-A15L], and insert [Sony Model MDR-E225]) were investigated. Twelve adult men served as subjects. Frequency response, high frequency average (HFA) output, peak output, peak output frequency, and overall RMS output for each PSS earphone were obtained with a probe tube microphone system (Fonix 6500 Hearing Aid Test System). Results indicated a significant difference in mean RMS outputs with nonsignificant differences in mean HFA outputs, peak outputs, and peak output frequencies among PSS earphones. Differences in mean overall RMS outputs were attributed to differences in low-frequency effects that were observed among the frequency responses of the three PSS earphones. It is suggested that one cannot assume equivalent real ear SPLs, with equivalent inputs, among different styles of PSS earphones.

Personal Audio System: Hearing Symptoms, Habits, and Sound Pressure Levels Measured in Real Ear and a Manikin

2020 ◽  
Vol 63 (6) ◽  
pp. 2016-2026
Author(s):  
Tamara R. Almeida ◽  
Clayton H. Rocha ◽  
Camila M. Rabelo ◽  
Raquel F. Gomes ◽  
Ivone F. Neves-Lobo ◽  
...  
Keyword(s):  
Sound Pressure ◽  
Daily Basis ◽  
Cross Sectional Study ◽  
Normal Hearing ◽  
Chi Square ◽  
Cross Sectional ◽  
The Real ◽  
Significant Difference ◽  
Sound Pressure Levels ◽  
Audio System

Purpose The aims of this study were to characterize hearing symptoms, habits, and sound pressure levels (SPLs) of personal audio system (PAS) used by young adults; estimate the risk of developing hearing loss and assess whether instructions given to users led to behavioral changes; and propose recommendations for PAS users. Method A cross-sectional study was performed in 50 subjects with normal hearing. Procedures included questionnaire and measurement of PAS SPLs (real ear and manikin) through the users' own headphones and devices while they listened to four songs. After 1 year, 30 subjects answered questions about their usage habits. For the statistical analysis, one-way analysis of variance, Tukey's post hoc test, Lin and Spearman coefficients, the chi-square test, and logistic regression were used. Results Most subjects listened to music every day, usually in noisy environments. Sixty percent of the subjects reported hearing symptoms after using a PAS. Substantial variability in the equivalent music listening level (Leq) was noted ( M = 84.7 dBA; min = 65.1 dBA, max = 97.5 dBA). A significant difference was found only in the 4-kHz band when comparing the real-ear and manikin techniques. Based on the Leq, 38% of the individuals exceeded the maximum daily time allowance. Comparison of the subjects according to the maximum allowed daily exposure time revealed a higher number of hearing complaints from people with greater exposure. After 1 year, 43% of the subjects reduced their usage time, and 70% reduced the volume. A volume not exceeding 80% was recommended, and at this volume, the maximum usage time should be 160 min. Conclusions The habit of listening to music at high intensities on a daily basis seems to cause hearing symptoms, even in individuals with normal hearing. The real-ear and manikin techniques produced similar results. Providing instructions on this topic combined with measuring PAS SPLs may be an appropriate strategy for raising the awareness of people who are at risk. Supplemental Material https://doi.org/10.23641/asha.12431435

First description of a glass sponge reef soundscape reveals fish calls and elevated sound pressure levels

2018 ◽  
Vol 595 ◽  
pp. 245-252 ◽  
Author(s):  
SK Archer ◽  
WD Halliday ◽  
A Riera ◽  
X Mouy ◽  
MK Pine ◽  
...  
Keyword(s):  
Sound Pressure ◽  
Glass Sponge ◽  
Sound Pressure Levels ◽  
Sponge Reef
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