The role of recovered envelope cues in the identification of temporal-fine-structure speech for hearing-impaired listeners

Narrowband speech can be separated into fast temporal cues [temporal fine structure (TFS)], and slow amplitude modulations (envelope). Speech processed to contain only TFS leads to envelope recovery through cochlear filtering, which has been suggested to account for TFS-speech intelligibility for normal-hearing listeners. Hearing-impaired listeners have deficits with TFS-speech identification, but the contribution of recovered-envelope cues to these deficits is unknown. This was assessed for hearing-impaired listeners by measuring identification of disyllables processed to contain TFS or recovered-envelope cues. Hearing-impaired listeners performed worse than normal-hearing listeners, but TFS-speech intelligibility was accounted for by recovered-envelope cues for both groups.National Institutes of Health (U.S.) (Grant R43 DC013006)National Institutes of Health (U.S.) (Grant R01 DC00117

Level variations in speech: Effect on masking release in hearing-impaired listeners

Acoustic speech is marked by time-varying changes in the amplitude envelope that may pose difficulties for hearing-impaired listeners. Removal of these variations (e.g., by the Hilbert transform) could improve speech reception for such listeners, particularly in fluctuating interference. Léger, Reed, Desloge, Swaminathan, and Braida [(2015b). J. Acoust. Soc. Am. 138, 389–403] observed that a normalized measure of masking release obtained for hearing-impaired listeners using speech processed to preserve temporal fine-structure (TFS) cues was larger than that for unprocessed or envelope-based speech. This study measured masking release for two other speech signals in which level variations were minimal: peak clipping and TFS processing of an envelope signal. Consonant identification was measured for hearing-impaired listeners in backgrounds of continuous and fluctuating speech-shaped noise. The normalized masking release obtained using speech with normal variations in overall level was substantially less than that observed using speech processed to achieve highly restricted level variations. These results suggest that the performance of hearing-impaired listeners in fluctuating noise may be improved by signal processing that leads to a decrease in stimulus level variations.National Institutes of Health (U.S.) (R01DC000117

Auditory and tactile gap discrimination by observers with normal and impaired hearing

Temporal processing ability for the senses of hearing and touch was examined through the measurement of gap-duration discrimination thresholds (GDDTs) employing the same low-frequency sinusoidal stimuli in both modalities. GDDTs were measured in three groups of observers (normal-hearing, hearing-impaired, and normal-hearing with simulated hearing loss) covering an age range of 21–69 yr. GDDTs for a baseline gap of 6 ms were measured for four different combinations of 100-ms leading and trailing markers (250–250, 250–400, 400–250, and 400–400 Hz). Auditory measurements were obtained for monaural presentation over headphones and tactile measurements were obtained using sinusoidal vibrations presented to the left middle finger. The auditory GDDTs of the hearing-impaired listeners, which were larger than those of the normal-hearing observers, were well-reproduced in the listeners with simulated loss. The magnitude of the GDDT was generally independent of modality and showed effects of age in both modalities. The use of different-frequency compared to same-frequency markers led to a greater deterioration in auditory GDDTs compared to tactile GDDTs and may reflect differences in bandwidth properties between the two sensory systems.National Institute on Deafness and Other Communication Disorders (U.S.) (Grant R01 DC000117

Ontologia III

Ontologia IIILivro didático de Ontologia III preparado para o curso EaD Licenciatura em Filosofia da UFSC. Tópicos abordados: A noção de entidade e a tarefa da ontologia; Realismo, Nominalismo e Conceptualismo; O quadrado ontológico e as formas de predicação;Dependência Ontológica e Relações Conceituais; Sobre os objetos intencionais; Noções de Ontologia da Realidade Social; A Ontologia da Obra de Arte em Ingarden; A noção de realidade virtual.Ua

Cross-Frequency Integration for Consonant and Vowel Identification in Bimodal Hearing

Purpose: Improved speech recognition in binaurally combined acoustic–electric stimulation (otherwise known as bimodal hearing) could arise when listeners integrate speech cues from the acoustic and electric hearing. The aims of this study were (a) to identify speech cues extracted in electric hearing and residual acoustic hearing in the low-frequency region and (b) to investigate cochlear implant (CI) users' ability to integrate speech cues across frequencies. Method: Normal-hearing (NH) and CI subjects participated in consonant and vowel identification tasks. Each subject was tested in 3 listening conditions: CI alone (vocoder speech for NH), hearing aid (HA) alone (low-pass filtered speech for NH), and both. Integration ability for each subject was evaluated using a model of optimal integration—the PreLabeling integration model (Braida, 1991). Results: Only a few CI listeners demonstrated bimodal benefit for phoneme identification in quiet. Speech cues extracted from the CI and the HA were highly redundant for consonants but were complementary for vowels. CI listeners also exhibited reduced integration ability for both consonant and vowel identification compared with their NH counterparts. Conclusion: These findings suggest that reduced bimodal benefits in CI listeners are due to insufficient complementary speech cues across ears, a decrease in integration ability, or both.National Organization for Hearing ResearchNational Institute on Deafness and Other Communication Disorders (U.S.) (Grant R03 DC009684-01)National Institute on Deafness and Other Communication Disorders (U.S.) (Grant R01 DC007152-02

Padronização de métodos para análise granulométrica no Brasil.

bitstream/item/96926/1/ComTec-66-Analise-Granulometrica.pd

Carbenic nitrile imines: Properties and reactivity

Structures and properties of nitrile imines were investigated computationally at B3LYP and CCSD(T) levels. Whereas NBO analysis at the B3LYP DFT level invariably predicts a propargylic electronic structure, CCSD(T) calculations permit a clear distinction between propargylic, allenic, and carbenic structures. Nitrile imines with strong IR absorptions above ca. 2150 cm-1 have propargylic structures with a CN triple bond (RCNNSiMe 3 and R2BCNNBR2), and those with IR absorptions below ca. 2150 cm-1 are allenic (HCNNH, PhCNNH, and HCNNPh). Nitrile imines lacking significant cumulenic IR absorptions at 1900-2200 cm -1 are carbenic (R-(C:)-N=N-R′). Electronegative but lone pair-donating groups NR2, OR, and F stabilize the carbenic form of nitrile imines in the same way they stabilize "normal" singlet carbenes, including N-heterocyclic carbenes. NBO analyses at the CCSD(T) level confirm the classification into propargylic, allenic, and carbenic reactivity types. Carbenic nitrile imines are predicted to form azoketenes 21 with CO, to form [2+2] and [2+4] cycloadducts and borane adducts, and to cyclize to 1H-diazirenes of the type 24 in mildly exothermic reactions with activation energies in the range 29-38 kcal/mol. Such reactions will be readily accessible photochemically and thermally, e.g., under the conditions of matrix photolysis and flash vacuum thermolysis

Communication Biophysics

Contains reports on five research projects.National Institutes of Health (Grant 5 RO1 NB-05462-02)National Aeronautics and Space Administration (Grant NsG-496)National Science Foundation (Grant GP-2495)National Institutes of Health (Grant MH-04737-05

Violent behavior of patients living in psychiatric residential facilities: A comparison of male patients with different violence histories

People with severe mental disorders and a history of violence are often seen as a difficult-to-manage segment of the population. In addition, this group is usually characterized by a high risk of crime recidivism, and poor compliance with community and aftercare programs. To investigate a sample of male patients living in Residential Facilities (RFs) with a history of violent behavior against people and to compare their characteristics with those of never-violent residents; to analyze the associations between aggressive behaviors in the last two years and a history of previous violence; and, to assess the predictors of aggressive behaviors. This study is part of a prospective observational cohort study which involved 23 RFs in Northern Italy. A comprehensive set of sociodemographic, clinical, and treatment-related information was gathered, and standardized assessments were administered to each participant. Also a detailed assessment of aggressive behaviors in the past two years was carried out. The study involved 268 males: 81 violent and 187 never-violent. Compared to never-violent patients, violent patients were younger, with a higher proportion of personality disorders, and have displayed an increased number of aggressive behaviors in the last two years. The presence of a history of violent behavior in the past significantly increases the probability of committing aggressive acts in the future