121 research outputs found

    Intelligibility of average talkers in typical listening environments,”

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    Intelligibility of conversationally produced speech for normal hearing listeners was studied for three male and three female talkers. Four typical listening environments were used. These simulated a quiet living room, a classroom, and social events in two settings with different reverberation characteristics. For each talker, overall intelligibility and intelligibility for vowels, consonant voicing, consonant continuance, and consonant place were quantified using the speech pattern contrast (SPAC) test. Results indicated that significant intelligibility differences are observed among normal talkers even in listening environments that permit essentially full intelligibility for everyday conversations. On the whole, talkers maintained their relative intelligibility across the four environments, although there was one exception which suggested that some voices may be particularly susceptible to degradation due to reverberation. Consonant place was the most poorly perceived feature, followed by continuance, voicing, and vowel intelligibility. However, there were numerous significant interactions between talkers and speech features, indicating that a talker of average overall intelligibility may produce certain speech features with intelligibility that is considerably higher or lower than average. Neither long-term rms speech spectrum nor articulation rate was found to be an adequate single criterion for selecting a talker of average intelligibility. Ultimately, an average talker was chosen on the basis of four speech contrasts: initial consonant place, and final consonant place, voicing, and continuance. and Taken together, these reports lead to the conclusion that when a speech intelligibility test is used to determine either (a) which of several hearing aids provides the most improvement in speech understanding, or (b) the absolute amount of improvement provided bY a particular instrument, the outcome will depend partly on the characteristics of the talker used to record the test materials and on the manner in which the materials are generated (conversational or clear). It is perhaps surprising that relatively little investigative attention has been paid to the issues involved in selection of talkers for speech intelligibility tests. When a new intelligibility test is reported, the talker is typically described as lacking a pronounced regional accent: There are no other criteria commonly applied in talker selection. However, if the test results are used to predict heating aid benefit for understanding everyday speech, it would appear, from the studies cited above, that care Should be taken to assure that the talker's speech is average in intelligibility and that the speech itself is delivered in a conversational/ normal manner when the test materials are recorded. A review of the literature failed to reveal any investigations that provided analytic data describing the intelligibility, for normal heating listeners, of normal talkers producing conversational speech in everyday listening settings. Hence, the present study was undertaken in an attempt to generate these data. The ultimate purpose in developing a description of the intelligibility of normal talkers was to provide a basis for selecting a talker of average intelligibility. In future work the chosen talker will produce speech materials for a speech intelligibility test to be used to quantify hearing aid benefit. Each talker's long-term rms 1/3-oct-band speech spectrum is shown in The SPAC test words were embedded in the sentences shown in Appendix A. These sentences were devised to present the items in a variety of contexts (as occurs in everday speech) with respect to preceding and following phonemes, position of test item in the utterance, and length of utterance. For each subtest, the 12 sentences were randomly assigned to the 12 test items. Each form (consisting of four subtests) was preceded by four practice items. Sentences for the practice items are also given in Appendix A. L Production of master recordings There For this talker combination, EH was rerecorded in environment A, FH was used in environment B, GF was used in environment C1, and EF was used in environment C2. Different combinations of two forms were used in the reduced intelligibility conditions, described below; all forms were used an equal number of times overall. The recordings of the six talkers were presented at an equal integrated rms level. To adjust the SPAC items appropriately for each environment, the recording for talker β€’ 1 was adjusted to achieve the primary message level (in dB Lβ€’ ) for that environment. The remaining talkers were presented at the same overall level as talker # 1. Hence, the spectra shown in The two SPAC forms recorded for each talker in each basic listening environment will be referred to as "typical intelligibility" conditions because they were adjusted to S/B ratio values that are maintained by normal talkers and listeners to yield essentially full intelligibility for conversations in these environments (according to the data of Pearsons etal., 1977). In addition, the remaining two SPAC forms for each talker were recorded in the same settings but with the background noise level increased sufficiently to reduce all contrast scores to less than 100%. The amount of increase in background noise necessary to achieve this differed across the four environments and was selected empirically in eac

    Hearing Aid Patients in Private Practice and Public Health (Veterans Affairs) Clinics: Are They Different?

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    Objective: In hearing aid research, it is commonplace to combine data across subjects whose hearing aids were provided in different service delivery models. There is reason to question whether these types of patients are always similar enough to justify this practice. To explore this matter, this investigation evaluated similarities and differences in self-report data obtained from hearing aid patients derived from public health (Veterans Affairs, VA) and private practice (PP) settings. Design: The study was a multisite, cross-sectional survey in which 230 hearing aid patients from VA and PP audiology clinic settings provided self-report data on a collection of questionnaires both before and after the hearing aid fitting. Subjects were all older adults with mild to moderately severe hearing loss. About half of them had previous experience wearing hearing aids. All subjects were fitted with wide-dynamic-range-compression instruments and received similar treatment protocols. Results: Numerous statistically significant differences were observed between the VA and PP subject groups. Before the fitting, VA patients reported higher expectations from the hearing aids and more severe unaided problems compared with PP patients with similar audiograms. Three wks after the fitting, VA patients reported more satisfaction with their hearing aids. On some measures VA patients reported more benefit, but different measures of benefit did not give completely consistent results. Both groups reported using the hearing aids an average of approximately 8 hrs per day. VA patients reported age-normal physical and mental health, but PP patients tended to report better than typical health for their age group. Conclusions: These data indicate that hearing aid patients seen in the VA public health hearing services are systematically different in self-report domains from those seen in private practice services. It is therefore risky to casually combine data from these two types of subjects or to generalize research results from one group to the other. Further, compared with PP patients, VA patients consistently reported more favorable hearing aid fitting outcomes. Additional study is indicated to explore the determinants of this result and its generalizability to other public health service delivery systems such as those in other countries. Moreover, efforts should be made to assess the potential for transferring positive elements from the VA system to the PP service delivery system, if possible. (Ear & Hearing 2005;26;513-528) It is arguable that audiology in the United States had its origins in the programs designed to provide rehabilitation for veterans who had sustained hearing damage as a result of military service in World War II. One of the major components of those programs was provision of amplification and counseling about its use. Since that time, the Department of Veterans Affairs (VA) has been a major supporter of research oriented toward the acquisition of scientific and clinical knowledge about provision of hearing aids for adults. A large volume of literature has accumulated describing the results of experiments that have featured hearing-impaired veterans as subjects. These patients receive services in a public health system in which public funds are used to provide services to improve or protect the health of veterans. At least two other entities have supported and produced research exploring hearing aids and fitting methods: hearing aid manufacturers and academic institutions such as universities and the National Institutes of Health. Many of the subjects serving in these studies were recruited from sources that would not be classified as public health services, such as free-standing dispensing practices or university-based dispensing clinics. In this article, patients seen in free-standing dispensing practices are classified as receiving services in a private practice (PP) system. University-based clinics might differ from freestanding dispensaries along several dimensions. a Some university-based clinics operate in a way that is similar to a private practice, whereas others do not follow this model. The VA public health service delivery setting is different in several key respects from most PP service delivery settings. The VA clinic is usually lo

    Development of APHAB norms of WDRC hearing aids and comparisons with original norms.

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    Objectives: This study was undertaken for two purposes: First, to provide a comparison of subjective performance and benefit measured with the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire for two groups. One group included hearing-impaired individuals using 1990s-era linear processing hearing aids. The other group included hearing-impaired individuals using more current wide-dynamic range compression (WDRC)-capable hearing aids fit using current practice protocols. The second purpose of this study was to determine whether APHAB norms derived from scores for current hearing aid users were different from the original 1995 norms. It was hypothesized that technology improvements would result in improved subjective performance for modern hearing aid wearers. Design: A systematic sampling method was used to identify and recruit subjects from seven private-practice audiology clinics located across the United States. Potential subjects were limited to older hearingimpaired individuals who were wearing hearing aids capable of WDRC processing. One hundred fifty-four subjects returned completed APHAB questionnaires. Participants reported mostly moderate to moderately severe subjective hearing difficulty. Results: No differences in perceived difficulty with speech communication were observed between the two groups. However, aversiveness of amplified sound was less frequently reported for users of WDRCcapable hearing aids. Norms were generated using data from all of the operationally defined successful hearing aid users in the sample and compared with the original 1995 norms. Differences between the 1995 and 2005 norms were minimal for the speech communication subscales. However, the 2005 group consistently reported less frequent difficulties with sound aversiveness (AV subscale) in the aided condition. In addition to these findings, an improvement was observed in the rate of successful adjustment to hearing aids between 1995 (43%) and 2005 (82%). Conclusions: Overall, problems understanding amplified speech did not decrease in frequency when hearing aids transitioned from linear to compression processing; however, the compression capabilities of current hearing aids (with a possible contribution from noise reduction algorithms) have resulted in less negative reactions to amplified environmental sounds. This suggests that modern technology has ameliorated (to some extent) the common complaint that hearing aids cause many everyday sounds to become objectionably loud. Although the results of this study suggest that the advantages of improved technology do not lie in the domains of improved subjective speech communication performance, substantial improvement in the rate of successful adjustment to hearing aids between the 1995 and 2005 subject groups provides evidence that modern hearing aid technology has produced progress in other outcome domains

    A detailed phenotypic assessment of individuals affected by MFRP-related oculopathy

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    Purpose: To determine the spectrum of mutations and phenotypic variability within patients with mutations in membrane-type frizzled related protein gene (MFRP).Methods: Individuals were initially ascertained based on a phenotype similar to that previously published in association with MFRP mutations. Affected patients underwent a full ophthalmic examination (best-corrected visual acuity, slit-lamp examination, applanation tonometry, and fundoscopy), color fundus photography, optical coherence tomography, autofluorescence imaging, and electrophysiology. MFRP was identified by a genome-wide scan in the fourth-largest autozygous region in one consanguineous family. Sanger sequencing of all the exons and intron-exon boundaries of MFRP was undertaken in the affected individuals.Results: Seven affected individuals from four families were identified as having mutations in MFRP. Patients from two families were homozygous for mutations already previously described (c. 1143_1144 insC and c. 492 delC), while those from the other two were compound heterozygous for mutations (c. 201G>A and c. 491_492 insT, and c. 492 delC, and c. 1622_1625 delTCTG), three of which were novel. There was considerable phenotypic variability within and among families. Autofluorescence imaging revealed the central macula to be relatively well preserved. Foveal cysts and optic nerve head drusen were present in two of the four families. Electrophysiology results showed rod-cone dystrophy with mild to moderate reduction in macular function in all affected members.Conclusions: We report three novel MFRP mutations and expand the phenotypic data available on patients with MFRP mutations

    Particulate Oxalate-To-Sulfate Ratio as an Aqueous Processing Marker: Similarity Across Field Campaigns and Limitations

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    Leveraging aerosol data from multiple airborne and surface-based field campaigns encompassing diverse environmental conditions, we calculate statistics of the oxalate-sulfate mass ratio (median: 0.0217; 95% confidence interval: 0.0154–0.0296; R = 0.76; N = 2,948). Ground-based measurements of the oxalate-sulfate ratio fall within our 95% confidence interval, suggesting the range is robust within the mixed layer for the submicrometer particle size range. We demonstrate that dust and biomass burning emissions can separately bias this ratio toward higher values by at least one order of magnitude. In the absence of these confounding factors, the 95% confidence interval of the ratio may be used to estimate the relative extent of aqueous processing by comparing inferred oxalate concentrations between air masses, with the assumption that sulfate primarily originates from aqueous processing

    Functional comparison of blood-stage Plasmodium falciparum malaria vaccine candidate antigens

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    The malaria genome encodes over 5,000 proteins and many of these have also been proposed to be potential vaccine candidates, although few of these have been tested clinically. RH5 is one of the leading blood-stage Plasmodium falciparum malaria vaccine antigens and Phase I/II clinical trials of vaccines containing this antigen are currently underway. Its likely mechanism of action is to elicit antibodies that can neutralize merozoites by blocking their invasion of red blood cells (RBC). However, many other antigens could also elicit neutralizing antibodies against the merozoite, and most of these have never been compared directly to RH5. The objective of this study was to compare a range of blood-stage antigens to RH5, to identify any antigens that outperform or synergize with anti-RH5 antibodies. We selected 55 gene products, covering 15 candidate antigens that have been described in the literature and 40 genes selected on the basis of bioinformatics functional prediction. We were able to make 20 protein-in-adjuvant vaccines from the original selection. Of these, S-antigen and CyRPA robustly elicited antibodies with neutralizing properties. Anti-CyRPA IgG generally showed additive GIA with anti-RH5 IgG, although high levels of anti-CyRPA-specific rabbit polyclonal IgG were required to achieve 50% GIA. Our data suggest that further vaccine antigen screening efforts are required to identify a second merozoite target with similar antibody-susceptibility to RH5

    BALB/c Mice Deficient in CD4+ T Cell IL-4RΞ± Expression Control Leishmania mexicana Load although Female but Not Male Mice Develop a Healer Phenotype

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    Immunologically intact BALB/c mice infected with Leishmania mexicana develop non-healing progressively growing lesions associated with a biased Th2 response while similarly infected IL-4RΞ±-deficient mice fail to develop lesions and develop a robust Th1 response. In order to determine the functional target(s) for IL-4/IL-13 inducing non-healing disease, the course of L. mexicana infection was monitored in mice lacking IL-4RΞ± expression in specific cellular compartments. A deficiency of IL-4RΞ± expression on macrophages/neutrophils (in LysMcreIL-4RΞ±βˆ’/lox animals) had minimal effect on the outcome of L. mexicana infection compared with control (IL-4RΞ±βˆ’/flox) mice. In contrast, CD4+ T cell specific (LckcreIL-4RΞ±βˆ’/lox) IL-4RΞ±βˆ’/βˆ’ mice infected with L. mexicana developed small lesions, which subsequently healed in female mice, but persisted in adult male mice. While a strong Th1 response was manifest in both male and female CD4+ T cell specific IL-4RΞ±βˆ’/βˆ’ mice infected with L. mexicana, induction of IL-4 was manifest in males but not females, independently of CD4+ T cell IL-4 responsiveness. Similar results were obtained using pan-T cell specific (iLckcreIL-4RΞ±βˆ’/lox) IL-4RΞ±βˆ’/βˆ’ mice. Collectively these data demonstrate that upon infection with L. mexicana, initial lesion growth in BALB/c mice is dependent on non-T cell population(s) responsive to IL-4/IL-13 while progressive infection is dependent on CD4+ T cells responsive to IL-4

    Having a lot of a good thing: multiple important group memberships as a source of self-esteem.

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    Copyright: Β© 2015 Jetten et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedMembership in important social groups can promote a positive identity. We propose and test an identity resource model in which personal self-esteem is boosted by membership in additional important social groups. Belonging to multiple important group memberships predicts personal self-esteem in children (Study 1a), older adults (Study 1b), and former residents of a homeless shelter (Study 1c). Study 2 shows that the effects of multiple important group memberships on personal self-esteem are not reducible to number of interpersonal ties. Studies 3a and 3b provide longitudinal evidence that multiple important group memberships predict personal self-esteem over time. Studies 4 and 5 show that collective self-esteem mediates this effect, suggesting that membership in multiple important groups boosts personal self-esteem because people take pride in, and derive meaning from, important group memberships. Discussion focuses on when and why important group memberships act as a social resource that fuels personal self-esteem.This study was supported by 1. Australian Research Council Future Fellowship (FT110100238) awarded to Jolanda Jetten (see http://www.arc.gov.au) 2. Australian Research Council Linkage Grant (LP110200437) to Jolanda Jetten and Genevieve Dingle (see http://www.arc.gov.au) 3. support from the Canadian Institute for Advanced Research Social Interactions, Identity and Well-Being Program to Nyla Branscombe, S. Alexander Haslam, and Catherine Haslam (see http://www.cifar.ca)

    A Radio Flare in the Long-Lived Afterglow of the Distant Short GRB 210726A: Energy Injection or a Reverse Shock from Shell Collisions?

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    We present the discovery of the radio afterglow of the short Ξ³\gamma-ray burst (GRB) 210726A, localized to a galaxy at a photometric redshift of z∼2.4z\sim 2.4. While radio observations commenced ≲1Β \lesssim 1~day after the burst, no radio emission was detected until ∼11\sim11~days. The radio afterglow subsequently brightened by a factor of ∼3\sim 3 in the span of a week, followed by a rapid decay (a ``radio flare''). We find that a forward shock afterglow model cannot self-consistently describe the multi-wavelength X-ray and radio data, and underpredicts the flux of the radio flare by a factor of β‰ˆ5\approx 5. We find that the addition of substantial energy injection, which increases the isotropic kinetic energy of the burst by a factor of β‰ˆ4\approx 4, or a reverse shock from a shell collision are viable solutions to match the broad-band behavior. At z∼2.4z\sim 2.4, GRB\,210726A is among the highest redshift short GRBs discovered to date as well as the most luminous in radio and X-rays. Combining and comparing all previous radio afterglow observations of short GRBs, we find that the majority of published radio searches conclude by ≲10Β \lesssim 10~days after the burst, potentially missing these late rising, luminous radio afterglows.Comment: 28 pages, 10 figures, submitted to Ap

    Short GRB Host Galaxies I: Photometric and Spectroscopic Catalogs, Host Associations, and Galactocentric Offsets

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    We present a comprehensive optical and near-infrared census of the fields of 90 short gamma-ray bursts (GRBs) discovered in 2005-2021, constituting all short GRBs for which host galaxy associations are feasible (β‰ˆ\approx 60% of the total Swift short GRB population). We contribute 245 new multi-band imaging observations across 49 distinct GRBs and 25 spectra of their host galaxies. Supplemented by literature and archival survey data, the catalog contains 335 photometric and 40 spectroscopic data sets. The photometric catalog reaches 3Οƒ3\sigma depths of ≳24βˆ’27\gtrsim 24-27 mag and ≳23βˆ’26\gtrsim 23-26 mag for the optical and near-infrared bands, respectively. We identify host galaxies for 84 bursts, in which the most robust associations make up 54% (49/90) of events, while only a small fraction, 6.7%, have inconclusive host associations. Based on new spectroscopy, we determine 17 host spectroscopic redshifts with a range of zβ‰ˆ0.15βˆ’1.6z\approx 0.15-1.6 and find that β‰ˆ\approx 25-44% of Swift short GRBs originate from z>1z>1. We also present the galactocentric offset catalog for 83 short GRBs. Taking into account the large range of individual measurement uncertainties, we find a median of projected offset of β‰ˆ7.9\approx 7.9 kpc, for which the bursts with the most robust associations have a smaller median of β‰ˆ4.9\approx 4.9 kpc. Our catalog captures more high-redshift and low-luminosity hosts, and more highly-offset bursts than previously found, thereby diversifying the population of known short GRB hosts and properties. In terms of locations and host luminosities, the populations of short GRBs with and without detectable extended emission are statistically indistinguishable. This suggests that they arise from the same progenitors, or from multiple progenitors which form and evolve in similar environments. All of the data products are available on the BRIGHT website.Comment: 53 pages, 9 figures, 6 tables, submitte
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