Effects of Speech Materials on the Loudness Discomfort Level

1979 ◽  
Vol 44 (4) ◽  
pp. 435-458 ◽  
Author(s):  
Randall C. Beattie ◽  
Bradly J. Edgerton ◽  
David W. Gager

Clinicians have used speech stimuli when measuring the loudness discomfort level (LDL) to determine the upper intensity limit for test stimulus presentation, and to select the saturation sound pressure level for an individual’s hearing aid. Because little research has investigated the effects of speech stimuli on the LDL, this study was undertaken to compare LDLs using six commercially available speech materials on 120 normally hearing listeners. Our comparisons showed no significant differences between the mean scores for any of the speech stimuli. These findings suggest that any differences in the mean LDLs among studies probably are not attributable to the speech stimuli. The intrasession reliability of LDL measurement was also assessed using a modified method of limits procedure with 2-dB increments and instructions stressing initial discomfort. It was concluded that examiners probably could attain a high degree of reliability by simply averaging the results of two ascending trials, because 95% of these test/retest differences did not exceed 6 dB. Our findings were integrated with previous studies in terms of: (1) test stimuli; (2) listener experience; (3) instructional set; and (4) psychophysical method. This discussion points to many unanswered questions and concludes that the LDL should be interpreted very cautiously. Moreover, it is suggested that the stimuli selected for LDL measurement should reflect the examiner’s purpose.

2010 ◽  
Vol 664 ◽  
pp. 510-539 ◽  
Author(s):  
M. Z. AFSAR

Measurements of subsonic air jets show that the peak noise usually occurs when observations are made at small angles to the jet axis. In this paper, we develop further understanding of the mathematical properties of this peak noise by analysing the properties of the overall sound pressure level with an acoustic analogy using isotropy as a paradigm for the turbulence. The analogy is based upon the hyperbolic conservation form of the Euler equations derived by Goldstein (Intl J. Aeroacoust., vol. 1, 2002, p. 1). The mean flow and the turbulence properties are defined by a Reynolds-averaged Navier–Stokes calculation, and we use Green's function based upon a parallel mean flow approximation. Our analysis in this paper shows that the jet noise spectrum can, in fact, be thought of as being composed of two terms, one that is significant at large observation angles and a second term that is especially dominant at small observation angles to the jet axis. This second term can account for the experimentally observed peak jet noise (Lush, J. Fluid Mech., vol. 46, 1971, p. 477) and was first identified by Goldstein (J. Fluid Mech., vol. 70, 1975, p. 595). We discuss the low-frequency asymptotic properties of this second term in order to understand its directional behaviour; we show, for example, that the sound power of this term is proportional to the square of the mean velocity gradient. We also show that this small-angle shear term does not exist if the instantaneous Reynolds stress source strength in the momentum equation itself is assumed to be isotropic for any value of time (as was done previously by Morris & Farrasat, AIAA J., vol. 40, 2002, p. 356). However, it will be significant if the auto-covariance of the Reynolds stress source, when integrated over the vector separation, is taken to be isotropic in all of its tensor suffixes. Although the analysis shows that the sound pressure of this small-angle shear term is sensitive to the statistical properties of the turbulence, this work provides a foundation for a mathematical description of the two-source model of jet noise.


2013 ◽  
Vol 470 ◽  
pp. 984-987
Author(s):  
Yang Sheng Cai ◽  
Cheng Yun Zhang

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.


1967 ◽  
Vol 10 (2) ◽  
pp. 319-322 ◽  
Author(s):  
Sanford E. Gerber

A total of 150 normal, adult males classified into five age groups was tested for the auditory flutter frequency threshold by a method of limits. The five variables employed in the study were: age, ear, psychophysical method, sound pressure level, and sound-time ratio. The following conclusions were derived: (a) the auditory flutter frequency threshold varies with psychophysical method and sound-time ratio; and (b) the auditory flutter frequency threshold does not vary with age, ear, and sound intensity.


1975 ◽  
Vol 40 (1) ◽  
pp. 84-91 ◽  
Author(s):  
Randall C. Beattie ◽  
Dion V. Svihovec ◽  
Brad J. Edgerton

Using three speakers and 75 subjects, a 7.9-dB range in the relative intelligibility of the Central Institute for the Deaf (CID) spondees was found when they were presented via monitored live voice. This range is consistent with previous research and is considered unnecessarily large and detrimental to the efficiency and precision of the speech reception threshold (SRT) test. The exclusive use of 18 words that have a mean range of 1.5 dB is suggested. The slope of the 36-item spondee articulation function is 12% per decibel and is slightly steeper than previous research using the CID W-l recorded spondees. The slope for the suggested 18-item test is also about 12% per decibel. For the 36-item test the mean speech detection threshold (SDT) was 6.6 dB sound pressure level (SPL) and the mean SRT was 14.2 db SPL. The 7.6-dB difference between the two speech measures is consistent with previous research but the SRT is about 6 dB better than the 20 dB SPL recommended by ANSI 1969. For the suggested 18-item test, the mean SRT was 14.5 dB SPL, which was 7.9 dB above SDT. When the 18-item test is used, average normal hearing can be expected to be about 5.5 dB better than specified by ANSI 1969.


1982 ◽  
Vol 25 (4) ◽  
pp. 564-573 ◽  
Author(s):  
Monica McHenry ◽  
Alan Reich ◽  
Fred Minifie

The ability of excellent esophageal speakers to manipulate acoustical characteristics associated with intended syllabic stress was studied. Five excellent esophageal speakers and five sex- and age-matched normals produced 10 sentence pairs, each containing a bisyllabic stimulus item differing only in primary stress placement. The mean fundamental frequency, sound pressure level, and duration of the stressed and unstressed vowel nuclei were analyzed. Although some differences in absolute levels were apparent, only sound pressure level differences reached statistical significance. For both groups, intended primary stress was associated with a comparable pattern of increased fundamental frequency, sound pressure level, and duration. The present findings suggest that excellent esophageal speakers are capable of producing some correlates of primary syllabic stress in a fashion remarkably similar to but somewhat less consistent than normals. The implications of these data for long-range clinical planning are discussed.


Author(s):  
Ellen C. Haas ◽  
Judy Edworthy

Various pulse parameters, which were believed to affect the perceived urgency of multitone auditory warning signals, were investigated in a factorial experiment. The three independent variables included pulse fundamental frequency (200, 500, and 800 Hz), pulse sound pressure level above ambient (5, 25, and 40 dB sound pressure level [SPL]), and inter-pulse interval (0,250, and 500 ms). The psychophysical method of free-modulus magnitude estimation was used to measure subjective perceived urgency. Multivariate statistical analysis indicated that all independent variables and most variable interactions were significant. Perceived urgency increased as pulse level increased and inter-pulse interval decreased. Multidimensional scaling analysis indicated that signal level and inter-pulse interval were important in subject perception of signal similarity in terms of perceived urgency. Signals with high sound pressure levels and short inter-pulse intervals were perceived by subjects to have similar perceived urgency, as were signals with low sound pressure levels and long inter-pulse intervals.


2020 ◽  
Vol 63 (4) ◽  
pp. 931-947
Author(s):  
Teresa L. D. Hardy ◽  
Carol A. Boliek ◽  
Daniel Aalto ◽  
Justin Lewicke ◽  
Kristopher Wells ◽  
...  

Purpose The purpose of this study was twofold: (a) to identify a set of communication-based predictors (including both acoustic and gestural variables) of masculinity–femininity ratings and (b) to explore differences in ratings between audio and audiovisual presentation modes for transgender and cisgender communicators. Method The voices and gestures of a group of cisgender men and women ( n = 10 of each) and transgender women ( n = 20) communicators were recorded while they recounted the story of a cartoon using acoustic and motion capture recording systems. A total of 17 acoustic and gestural variables were measured from these recordings. A group of observers ( n = 20) rated each communicator's masculinity–femininity based on 30- to 45-s samples of the cartoon description presented in three modes: audio, visual, and audio visual. Visual and audiovisual stimuli contained point light displays standardized for size. Ratings were made using a direct magnitude estimation scale without modulus. Communication-based predictors of masculinity–femininity ratings were identified using multiple regression, and analysis of variance was used to determine the effect of presentation mode on perceptual ratings. Results Fundamental frequency, average vowel formant, and sound pressure level were identified as significant predictors of masculinity–femininity ratings for these communicators. Communicators were rated significantly more feminine in the audio than the audiovisual mode and unreliably in the visual-only mode. Conclusions Both study purposes were met. Results support continued emphasis on fundamental frequency and vocal tract resonance in voice and communication modification training with transgender individuals and provide evidence for the potential benefit of modifying sound pressure level, especially when a masculine presentation is desired.


2020 ◽  
Vol 68 (2) ◽  
pp. 137-145
Author(s):  
Yang Zhouo ◽  
Ming Gao ◽  
Suoying He ◽  
Yuetao Shi ◽  
Fengzhong Sun

Based on the basic theory of water droplets impact noise, the generation mechanism and calculation model of the water-splashing noise for natural draft wet cooling towers were established in this study, and then by means of the custom software, the water-splashing noise was studied under different water droplet diameters and water-spraying densities as well as partition water distribution patterns conditions. Comparedwith the water-splashing noise of the field test, the average difference of the theoretical and the measured value is 0.82 dB, which validates the accuracy of the established theoretical model. The results based on theoretical model showed that, when the water droplet diameters are smaller in cooling tower, the attenuation of total sound pressure level of the water-splashing noise is greater. From 0 m to 8 m away from the cooling tower, the sound pressure level of the watersplashing noise of 3 mm and 6 mm water droplets decreases by 8.20 dB and 4.36 dB, respectively. Additionally, when the water-spraying density becomes twice of the designed value, the sound pressure level of water-splashing noise all increases by 3.01 dB for the cooling towers of 300 MW, 600 MW and 1000 MW units. Finally, under the partition water distribution patterns, the change of the sound pressure level is small. For the R s/2 and Rs/3 partition radius (Rs is the radius of water-spraying area), when the water-spraying density ratio between the outer and inner zone increases from 1 to 3, the sound pressure level of water-splashing noise increases by 0.7 dB and 0.3 dB, respectively.


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