Three Models of Temporal Summation Evaluated Using Normal-Hearing and Hearing-Impaired Subjects

1983 ◽  
Vol 26 (2) ◽  
pp. 256-262 ◽  
Author(s):  
George M. Gerken ◽  
Adele D. Gunnarson ◽  
Craig M. Allen

Temporal summation effects were measured in normal-hearing and hearing impaired subjects using stimuli of different durations and temporal patterns. Threshold decreased with increasing stimulus duration for either single- or multiple-burst stimuli, but the hearing-impaired group showed smaller threshold shifts, which differed from those obtained with the normal-hearing group at the .0001 level of significance. Three models of temporal summation were evaluated: One model employed a time constant in an exponential function, one used a power function characterized by an exponent, and the last combined the properties of the exponential and power functions and was also characterized by an exponent. Estimates of the parameters that best described the data were obtained for each model. Data from the hearing-impaired subjects provided the most critical test of the models. The power function model and the combined model were both satisfactory with the range of stimulus durations used. but the exponential model failed to describe the data from the hearing-impaired subjects. It is suggested that there may not be a decrease in the time constant for temporal summation for subjects with sensorineural hearing-loss but that a factor related to the utilization of sensory input is altered.

1989 ◽  
Vol 32 (2) ◽  
pp. 298-306 ◽  
Author(s):  
David A. Nelson ◽  
Rosemary Pavlov

Previous research has shown that frequency-specific estimates of auditory time constants for recovery from short-term adaptation can be made using a fixed-probe forward-masking procedure (Nelson & Freyman, 1987) if the masker and the probe stimuli are at the same frequency. This study examines the validity of time-constant estimates for off-frequency forward-masking conditions in which the masker frequency is below (900 Hz) or above (1100 Hz) the probe frequency (1000 Hz). Fixed-probe-level temporal masking functions were obtained from four normal-hearing and four hearing-impaired listeners. Auditory time constants were estimated with iterative least-squares procedures to derive parameter values for an exponential model of recovery from forward masking. After appropriate corrections were made for attenuation to the maskers provided by the auditory filter centered at the probe frequency, recovery from forward masking produced by either off-frequency or on-frequency maskers could be described by a single time constant. That time constant was around 50 ms in normal-hearing listeners and was larger in those hearing-impaired listeners who demonstrated moderate hearing loss at the probe frequency.


2020 ◽  
Vol 63 (4) ◽  
pp. 1299-1311 ◽  
Author(s):  
Timothy Beechey ◽  
Jörg M. Buchholz ◽  
Gitte Keidser

Objectives This study investigates the hypothesis that hearing aid amplification reduces effort within conversation for both hearing aid wearers and their communication partners. Levels of effort, in the form of speech production modifications, required to maintain successful spoken communication in a range of acoustic environments are compared to earlier reported results measured in unaided conversation conditions. Design Fifteen young adult normal-hearing participants and 15 older adult hearing-impaired participants were tested in pairs. Each pair consisted of one young normal-hearing participant and one older hearing-impaired participant. Hearing-impaired participants received directional hearing aid amplification, according to their audiogram, via a master hearing aid with gain provided according to the NAL-NL2 fitting formula. Pairs of participants were required to take part in naturalistic conversations through the use of a referential communication task. Each pair took part in five conversations, each of 5-min duration. During each conversation, participants were exposed to one of five different realistic acoustic environments presented through highly open headphones. The ordering of acoustic environments across experimental blocks was pseudorandomized. Resulting recordings of conversational speech were analyzed to determine the magnitude of speech modifications, in terms of vocal level and spectrum, produced by normal-hearing talkers as a function of both acoustic environment and the degree of high-frequency average hearing impairment of their conversation partner. Results The magnitude of spectral modifications of speech produced by normal-hearing talkers during conversations with aided hearing-impaired interlocutors was smaller than the speech modifications observed during conversations between the same pairs of participants in the absence of hearing aid amplification. Conclusions The provision of hearing aid amplification reduces the effort required to maintain communication in adverse conditions. This reduction in effort provides benefit to hearing-impaired individuals and also to the conversation partners of hearing-impaired individuals. By considering the impact of amplification on both sides of dyadic conversations, this approach contributes to an increased understanding of the likely impact of hearing impairment on everyday communication.


2019 ◽  
pp. 39-55
Author(s):  
Osman Kusan ◽  
Hasan Erdem Mumcu ◽  
Abdulkerim Çeviker ◽  
Ömer Zambak ◽  
Onur Öztürk

This study was conducted to investigate the sub-scales of sports instructions of elite athletes with hearing impairment or hearing loss due to different reasons. A total of 173 hearing-impaired athletes constituted of 54 female and 119 male athletes who are active national team athletes in the age range of 15-25 years. The study was conducted based on Self Determination Theory of Deci and Ryan [9] and on the developed Sports Motivation Scale, Pelletier et al. [24] Kazak [18] applied the validity and reliability of the scale for Turkish athletes. Accordingly, since the p_values calculated for the inner motivation sub-scale and its sub-scales are less than the value of α = .05 which is taken as the level of significance, there is a statistically significant difference in the average scores of the hearing-impaired athletes in their internal motivations and sub-scales. According to gender and educational status, there was no difference in the motivation of the hearing-impaired athletes. According to the age variable, it was seen that older athletes had more external connections. Considering the general motivation scores, the athletes in tennis and swimming were less motivated than others. Elite hearing-impaired athletes are affected by both internal and external impulses. However, internal motivation scores are higher than the external. Internal motivation scores are seen as the lowest in the branch swimming area.


2021 ◽  
Author(s):  
Ryszard Mazurek

AbstractFor any commutative semigroup S and positive integer m the power function $$f: S \rightarrow S$$ f : S → S defined by $$f(x) = x^m$$ f ( x ) = x m is an endomorphism of S. We partly solve the Lesokhin–Oman problem of characterizing the commutative semigroups whose all endomorphisms are power functions. Namely, we prove that every endomorphism of a commutative monoid S is a power function if and only if S is a finite cyclic group, and that every endomorphism of a commutative ACCP-semigroup S with an idempotent is a power function if and only if S is a finite cyclic semigroup. Furthermore, we prove that every endomorphism of a nontrivial commutative atomic monoid S with 0, preserving 0 and 1, is a power function if and only if either S is a finite cyclic group with zero adjoined or S is a cyclic nilsemigroup with identity adjoined. We also prove that every endomorphism of a 2-generated commutative semigroup S without idempotents is a power function if and only if S is a subsemigroup of the infinite cyclic semigroup.


2019 ◽  
Vol 23 ◽  
pp. 233121651988761 ◽  
Author(s):  
Gilles Courtois ◽  
Vincent Grimaldi ◽  
Hervé Lissek ◽  
Philippe Estoppey ◽  
Eleftheria Georganti

The auditory system allows the estimation of the distance to sound-emitting objects using multiple spatial cues. In virtual acoustics over headphones, a prerequisite to render auditory distance impression is sound externalization, which denotes the perception of synthesized stimuli outside of the head. Prior studies have found that listeners with mild-to-moderate hearing loss are able to perceive auditory distance and are sensitive to externalization. However, this ability may be degraded by certain factors, such as non-linear amplification in hearing aids or the use of a remote wireless microphone. In this study, 10 normal-hearing and 20 moderate-to-profound hearing-impaired listeners were instructed to estimate the distance of stimuli processed with different methods yielding various perceived auditory distances in the vicinity of the listeners. Two different configurations of non-linear amplification were implemented, and a novel feature aiming to restore a sense of distance in wireless microphone systems was tested. The results showed that the hearing-impaired listeners, even those with a profound hearing loss, were able to discriminate nearby and far sounds that were equalized in level. Their perception of auditory distance was however more contracted than in normal-hearing listeners. Non-linear amplification was found to distort the original spatial cues, but no adverse effect on the ratings of auditory distance was evident. Finally, it was shown that the novel feature was successful in allowing the hearing-impaired participants to perceive externalized sounds with wireless microphone systems.


1979 ◽  
Vol 22 (2) ◽  
pp. 236-246 ◽  
Author(s):  
Jeffrey L. Danhauer ◽  
Ruth M. Lawarre

Perceptual patterns in rating dissimilarities among 24 CVs were investigated for a group of normal-hearing and two groups of hearing-impaired subjects (one group with flat, and one group with sloping, sensorineural losses). Stimuli were presented binaurally at most comfortable loudness level and subjects rated the 576 paired stimuli on a 1–7 equal-appearing interval scale. Ratings were submitted to individual group and combined INDSCAL analyses to describe features used by the subjects in their perception of the speech stimuli. Results revealed features such as sibilant, sonorant, plosive and place. Furthermore, normal and hearing-impaired subjects used similar features, and subjects' weightings of features were relatively independent of their audiometric configurations. Results are compared to those of previous studies.


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