Real Ear to 6-cm 3 Coupler Differences in Young Children

1993 ◽  
Vol 36 (1) ◽  
pp. 204-209 ◽  
Author(s):  
Dawna E. Lewis ◽  
Patricia G. Stelmachowicz
Keyword(s):  
Young Children ◽  
Pure Tone ◽  
Sound Pressure ◽  
Intersubject Variability ◽  
Frequency Range ◽  
Individual Basis ◽  
Sound Pressure Levels ◽  
Adults And Children ◽  
Speech Spectrum

Real-ear sound pressure levels under supra-aural earphones were measured for a group of young children (9 months to 7 years) and adults. Pure-tone signals were presented at nine test frequencies from 250 to 6000 Hz, and real ear to 6-cm 3 coupler differences were computed for each frequency. Results suggest that, by 2 years of age, average real ear to 6-cm 3 coupler differences are similar for adults and children. The intersubject variability for all groups supports the need for real-ear threshold measures on an individual basis in cases where the ability to amplify the speech spectrum to a level that is audible across the frequency range is in question.

scholarly journals ENVIROMENTAL ASPECTS OF NOISE ASSESSMENT AND REGULATION IN THE DESIGN OF PORT COMPLEXES IN RUSSIA

Akustika ◽  
2019 ◽  
Vol 34 ◽  
pp. 72-78
Author(s):  
Vladimir Zhigulski ◽  
Daria Zhigulskaya ◽  
Vladimir Shuisky ◽  
Ekaterina Chebynina ◽  
Vitaly Panichev
Keyword(s):  
Sound Pressure ◽  
Animal Species ◽  
Riparian Ecosystems ◽  
Frequency Range ◽  
Noise Levels ◽  
Natural Ecosystems ◽  
Physiological Processes ◽  
Sound Pressure Levels ◽  
Noise Assessment ◽  
Natural Test

A comparative analysis of various biological objects sensitivity to acoustic effects is being conducted. For many animal species, the frequency range at which sounds are heard is very different from that for humans and may not even intersect with it. The total frequency range at which various animals can hear covers at least eight orders of magnitude (from hundredths of Hz to hundreds of kHz), while for humans this interval is limited to only four orders of magnitude. Thus, the existing anthropocentric standards for permissible noise levels are unsuitable for regulating their impacts on natural ecosystems and it is necessary to develop standards for sound pressure levels in the entire specified frequency range that are acceptable for the most sensitive recipients. For terrestrial and riparian ecosystems and protected areas, natural test subjects are birds, for which noise levels of 35-40 dBA do not cause pathological changes in behavior and physiological processes. This level can tentatively be considered as maximum permissible for man-made noise and for the noise of ports in particular. More reliable results will be given by regulating the permissible sound pressure levels in the entire frequency range based on reactions of the most sensitive recipients in each octave.

Study of Sound Insulation of Control Cabins in Industry in the Low Frequency Range

1992 ◽  
Vol 11 (2) ◽  
pp. 42-46
Author(s):  
Anna Kaczmarska ◽  
Danuta Augustyriska
Keyword(s):  
Noise Reduction ◽  
Sound Pressure ◽  
Low Frequency ◽  
Machine Building ◽  
Sound Insulation ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Frequency Range ◽  
Sound Pressure Levels ◽  
Lower Frequencies

The number of control cabins installed in industry has increased considerably during the last few years. Most cabins installed nowadays show a satisfactory noise reduction in the frequency range above 500 Hz. The effect of noise damping however shows a gradual decrease for lower frequencies. The present paper is a description of the distribution of low frequency noise in different types of control cabins installed in typical low frequency noise environments in steel plants and the machine building industry. Measurements were made in 20 control cabins, constructed of metal and stone Measurements of sound pressure levels in octave bands were made inside and outside the cabins. The sound pressure level in octave bands in the low frequency range (4–31.5 Hz) inside the cabins was high and varied between 60–108 dB. This is probably due to the insufficient noise reduction for lower frequencies. In some control cabins there was an increased level of low frequency noise inside the cabin compared to the outside. In these control cabins sound pressure levels exceed the admissible values according to Polish standards. The increase of noise level within the low frequency range is considered to be based on resonances.

An Investigation of the Perception Thresholds of Band-Limited Low Frequency Noises: Influence of Bandwidth

2003 ◽  
Vol 22 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Yasunao Matsumoto ◽  
Yukio Takahashi ◽  
Setsuo Maeda ◽  
Hiroki Yamaguchi ◽  
Kazuhiro Yamada ◽  
...  
Keyword(s):  
Sound Pressure ◽  
Low Frequency ◽  
Frequency Range ◽  
Pass Filter ◽  
Sound Pressure Levels ◽  
Pure Tones ◽  
Band Limited ◽  
The One ◽  
Frequency Weighting ◽  
40 Hz

Perception thresholds of complex low frequency noises have been investigated in a laboratory experiment. Sound pressure levels that were just perceptible by subjects were measured for three complex noises and three pure tones. The complex noises had a flat constant spectrum over the frequency range 2 to 10, 20, or 40 Hz and decreased at 15 dB per octave at higher frequencies. The frequencies of the pure tones used in this study were 10, 20 and 40 Hz. The perception thresholds were obtained using an all-pass filter, one-third octave band filters, and the G frequency weighting defined in ISO 7196. The G-weighted sound pressure levels obtained were compared with 100 dB which is described in ISO 7196 as the G-weighted level corresponding to the threshold of sounds in the frequency range 1 to 20 Hz. The perception thresholds of the pure tones measured in this study were comparable to the results available in various previous studies. The one-third octave sound pressure levels obtained for the thresholds of the complex noises appeared to be lower than the measured thresholds of the pure tones. The G-weighted sound pressure levels obtained for the thresholds of the complex noises appeared to be lower than 100 dB.

Pure Tone-Spondee Threshold Relationships in Functional Hearing Loss: A Hypothesis

1976 ◽  
Vol 41 (1) ◽  
pp. 16-22 ◽  
Author(s):  
Ira M. Ventry
Keyword(s):  
Hearing Loss ◽  
Pure Tone ◽  
Sound Pressure ◽  
Speech Audiometry ◽  
Pure Tone Average ◽  
Sound Pressure Levels ◽  
Research Implication ◽  
Pure Tones ◽  
Response Decisions ◽  
Relationship Factors

A hypothesis is offered to account for the fact that in functional hearing loss, spondee threshold is frequently significantly lower than the pure-tone average. The hypothesis has three basic components: (1) that patients with functional hearing loss use a loudness criterion in making response decisions to suprathreshold stimuli; (2) that, at suprathreshold levels, pure tones and spondee words appear equally loud at equal sound pressure levels, and (3) that calibration values employed in pure-tone and speech audiometry contribute to the aberrant speech—pure tone relationship. Factors that may confound the speech—pure tone relationship are discussed as are the clinical and research implication of the hypothesis.

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

Sign in / Sign up

Export Citation Format

Share Document