Jean-Pierre Gagné

Optimal Outcome Measures, Research Priorities, and International Cooperation

&NA; The participants in the Eriksholm Workshop on “Measuring Outcomes in Audiological Rehabilitation Using Hearing Aids” debated three issues that are reported in this article. First, it was agreed that the characteristics of an optimal outcome measure vary as a function of the purpose of the measurement. Potential characteristics of outcome self‐report tools for four common goals of outcome measurement are briefly presented to illustrate this point. Second, 10 important research priorities in outcome measurement were identified and ranked. They are presented with brief discussion of the top five. Third, the concept of generating a brief universally applicable outcome measure was endorsed. This brief data set is intended to supplement existing outcome measures and to promote data combination and comparison across different social, cultural, and health‐care delivery systems. A set of seven core items is proposed for further study.

Sources and early diagenesis of lignin and bulk organic matter in the sediments of the Lower St. Lawrence Estuary and the Saguenay Fjord

Elemental and molecular organic matter concentrations were analyzed in sediments from the Lower St. Lawrence Estuary and the Saguenay Fjord in order to evaluate the historic evolution of pulp and paper mills solid-waste inputs in the system in the last decades and the relative reactivities of lignin and bulk organic materials in coastal sediments. A qualitative estimation of vascular plant sources to the Saguenay Fjord shows that the sedimentary terrigenous plant material is comprised predominantly of gymnosperm woods. In the deeper sediment horizons of the upper Saguenay basin, low intensive lignin parameters (C/V and S/V) and high percentages of lignin to total sedimentary organic carbon ( > 20%) all indicate elevated concentrations of woody gymnosperm tissues unprecedented in coastal sediments and directly related to the intense activity of the regions pulp and paper industries. The increased control on solid organic wastes from industrial effluents into the Saguenay river in the late 1980s to early 1990s is clearly apparent from increasing intensive parameter values and decreasing lignin fractions to the total sedimentary organic carbon (= 6-8%) in the upper basin surface sediments. Elemental and molecular analyses of fjord sediments, all indicate that most of the solid-phase discharge of lignified material by the pulp and paper industry is deposited rapidly close to the mouth of the river without reaching the downstream basins. In the St. Lawrence Estuary, intensive lignin parameters indicate that gymnosperm tissues are a major component of the sedimentary vascular plant material but with a significant fraction composed of angiosperm and nonwoody tissues. These latter types of organic tissues are particularly important components of terrigenous material in sediments deposited prior to the 1910-1920s. Acid/aldehyde ratios in most cores studied do not indicate clear-cut oxidative degradation of lignin material prior to its introduction in the aquatic system. The only exceptions are the two estuarine cores, where slightly elevated acid/aldehyde ratios relative to the range for fresh vascular plant tissues, might indicate mild aerobic fungal degradation of the sedimentary lignin material. Organic carbon, total nitrogen, organic phosphorus and lignin derived phenols all exhibited decreasing concentrations with core depth in the sediments of the Lower St. Lawrence Estuary. First-order degradation rate constants for all four chemical categories ranged between 0.02-0.05 yr -1 . The order of apparent reactivity among the different organic compounds is TN ≥ C org > P org > lignin at the head of the Laurentian channel and lignin TN = C org > P org further downstream. The surprising diagenetic selectivity observed at the upstream station is probably due to a higher flux of fresh, labile organic matter that reaches the sediment-water interface and degrades preferentially to more refractory materials such as lignin. Further downstream, little diagenetic selectivity was observed below the sediment-water interface indicating an overall refractory nature of the sedimentary organic matter. Finally, the differences in reactivity observed between C org and P org at both stations contradict earlier assumptions that no fractionation occurs between organic carbon and phosphorus during anaerobic degradation.

Early diagenetic processes in coastal marine sediments disturbed by a catastrophic sedimentation event

Abstract Following a catastrophic flash flood in July 1996, as much as 50 cm of post-glacial clays were deposited in less than 2 days in the upper reaches of the Saguenay Fjord (Quebec, Canada), disrupting the normal sedimentation and diagenetic regimes. We report detailed geochemical analyses of sediments (porosity, Eh, organic and inorganic carbon, Fe and Mn reactive solid phases, and acid volatile sulfide) and porewaters (salinity, dissolved organic carbon (DOC), Fe(II), Mn(II), nitrate, ammonium, and sulfate) for seven stations located in the Saguenay Fjord. Three of these (SAG-05, SAG-09, and SAG-30) were visited in 1996 and once per year thereafter to document the chemical evolution of the sediment toward a new steady state. The flood deposits contain less organic carbon and more inorganic carbon than the indigenous fjord sediments. The flood deposit modified the distribution patterns of reactive Mn and Fe as a result of the reduction of Mn and Fe oxides delivered with the deposit and those concentrated at the now buried former sediment-water interface. Most of the Mn(II) migrated to the new sediment-water interface, where a Mn-rich layer was formed. In contrast, much of the Fe(II) was precipitated as sulfides and remained trapped at or close to the old interface. A nitrate peak developed in the porewater at the old sediment-water interface, possibly because of the oxidation of ammonia by Mn oxides. The distributions of porewater DOC within the flood deposit correlate with the distributions of dissolved Mn(II) and Fe(II), suggesting that adsorbed DOC was released when metal oxides were reduced.

Visual stimuli can impair auditory processing in cochlear implant users

It has been shown that visual stimulation can activate cortical regions normally devoted to auditory processing in deaf individuals. This neural activity can persist even when audition is restored through the implantation of a cochlear implant, raising the possibility that cross-modal plasticity can be detrimental to auditory performance in cochlear implant users. To determine the influence of visual information on auditory performance after restoration of hearing in deaf individuals, the ability to segregate conflicting auditory and visual information was assessed in fourteen cochlear implant users with varied degree of expertise and an equal number of participants with normal-hearing matched for gender, age and hearing performance. An auditory speech recognition task was administered in the presence of three incongruent visual stimuli (color-shift, random-dot motion and lip movement). For proficient cochlear implant users, auditory performance was equal to that of controls in the three experimental conditions where visual stimuli were presented simultaneously with auditory information. For non-proficient cochlear implant users, performance did not differ from that of matched controls when the auditory stimulus was paired with a visual stimulus that was color-shifted. However, significant differences were observed between the non-proficient cochlear implant users and their matched controls when the accompanying visual stimuli consisted of a moving random-dot pattern or incongruent lip movements. These findings raise several questions with regards to the rehabilitation of cochlear implant users.

Ear level recordings of the long-term average spectrum of speech.

The long-term average speech spectrum (LTASS) was measured at two different recording positions: 30 cm directly in front of the talker (reference position), and at the tragus of the talkers ear (ear-level position), for three groups of subjects: adult males, adult females, and children. Results indicated significant differences in the overall level and frequency spectra between the LTASS obtained at each microphone location. For all three groups of subjects the LTASS measured at the ear-level position consisted of more low frequency energy (i.e., below 1000 Hz) and less high frequency energy (i.e., above 2500 Hz) than did the LTASS measured at the reference microphone position. The findings suggest that the algorithms currently used to prescribe hearing aid gain may underestimate the sensation level of a hearing-impaired individuals own amplified speech productions at frequencies below 1000 Hz and overestimate the sensation level of a talkers own speech above 2500 Hz. The implications of these findings concerning selection of the electroacoustic characteristics of an amplification system for hearing-impaired individuals are discussed.

Stigma: A negative and a positive influence on help-seeking for adults with acquired hearing loss

Abstract There are stigmas associated with many chronic health conditions that emerge in adulthood. People who present manifestations of hearing loss are often perceived by others to be cognitively diminished, less able, and socially incompetent. In order to avoid being identified as a member of a stigmatized group, individuals with hearing loss may choose not to seek health services or fail to comply with recommended treatments. The purpose of this study was to better understand how stigma impacted upon the help-seeking activities of adults with an acquired hearing loss. Ten people who had hearing loss, and were members of peer-support groups participated in audio-recorded semi-structured interviews. Verbatim transcripts were analysed using thematic analyses. Analyses revealed that lasting decisions about hearing loss management were made following ‘critical junctures’, when the negative stress found in the respondents social and physical environment far outweighed positive energy, or when the positive energy found in the respondents environment far outweighed the negative stress. The time course development of these processes is described. Sumario Existen estigmas asociados con muchas condiciones crónicas de salud que aparecen en la edad adulta. La gente que presenta manifestaciones de pérdida auditiva a menudo son percibidas por los demás como disminuidos cognitivamente, menos capaces, y socialmente incompetentes. Para evitar ser identificado como un miembro de un grupo estigmatizado, los individuos con hipoacusia escogen no buscar ayuda en los servicios de salud o fallan en cumplir con los tratamientos recomendados. El propósito de este estudio fue entender mejor cómo el estigma impacta las actividades de búsqueda de ayuda de adultos con hipoacusias adquiridas. Diez personas con pérdida auditiva, que era miembros de grupos de apoyo a iguales, participaron de entrevistas semi-estructuradas, grabadas en audio. Se analizaron las transcripciones usando un análisis temático. Los análisis revelaron las decisiones duraderas sobre el manejo de la hipoacusia se realizaban luego de “encrucijadas críticas”, cuando la tensión negativa encontrada en el ambiente social y físico del participante sobrepasaba la energía positiva, o cuando la energía positiva que se hallaba en el ambiente del participante sobrepasaba la tensión negativa. Se describe el desarrollo en el tiempo de estos procesos.

Older adults expend more listening effort than young adults recognizing audiovisual speech in noise

Abstract Objective: Using a dual task paradigm, two experiments were conducted to: (1) quantify the listening effort that young and older adults expend to recognize speech in noise when presented under audio-only (Experiment 1) and audiovisual conditions (Experiment 2) and, (2) determine the influence visual cues have on listening effort. Listening effort refers to the attentional and cognitive resources required to understand speech. Design: All participants performed a closed-set word recognition task and tactile pattern recognition task separately and concurrently. Accuracy and reaction time data were collected. The criterion for single task word recognition performance was set to 80% correct across experiments and across age groups. Study sample: For each experiment, 25 young and 25 older adults with normal hearing and normal (or corrected normal) vision participated. Results: Under equated performance conditions, older adults expended more listening effort than young adults with both audio-only and audiovisually presented speech. Furthermore, the processing demands of audiovisual speech recognition were greater than audio-only speech recognition for all participants. Conclusions: These results suggest that while visual cues can improve audiovisual speech recognition, they can also place an extra demand on processing resources with performance consequences for the word and tactile tasks under dual task conditions. Sumario Objetivo: Utilizando un paradigma de doble tarea, se realizaron dos experimentos: 1) cuantificar el esfuerzo que hace los adultos jóvenes y mayores para reconocer el lenguaje en ruido ciando se presenta solo en audio (experimento 1) y en condición audio-visual (experimento 2) y 2) determinar la influencia de las claves visuales en el esfuerzo por comprender. El esfuerzo comprensivo se refiere a los recursos cognitivos y de atención requeridos para comprender el lenguaje. Diseño: Todos los participantes realizaron una tarea de reconocimiento de palabras en contexto cerrado y una tarea de reconocimiento táctil separada y concomitantemente. Se colectaron los datos sobre la precisión y el tiempo de reacción. El criterio para el desempeñ en la prueba de tarea única de reconocimiento de palabras se fijó en 80% de aciertos a través de experimentos y a través de grupos etáreos. Muestra: Para cada experimento, participaron 25 adultos jóvenes y 25 adultos viejos con audición normal y visión normal (o normal corregida). Resultados: En condiciones equitativas de desempeño, los adultos mayores efectuaron mayor esfuerzo que los adultos jóvenes en ambas condiciones de presentación del discurso: sólo audio y audiovisual. Incluso la demanda audiovisual de procesamiento del discurso fue mayor que la auditiva en todos los participantes. Conclusiones: Estos resultados sugieren que mientras las claves visuales pueden mejorar el reconocimiento audiovisual del lenguaje, también demandan un esfuerzo extra en el procesamiento de recursos, con las consecuencias en el desempeño de las tareas táctiles y de palabras en la condición dual.

Auditory, visual and audiovisual clear speech☆

Abstract The speech intelligibility of syllables spoken under conditions of conversational and clear speech was compared. The stimuli were 18 monosyllables (/C-v/) and 18 bisyllables (/v-C-v/) consisting of six voiced-consonants (/b, d, g, v, z, ʒ /) presented in each of three vowel contexts (/a, i, y/). Six female adults were recorded while they produced four iterations of the stimulus set in each of the two speaking styles. The 1728 videotaped test items were edited, randomized and presented to 12 subjects with normal hearing and normal visual acuity under three conditions: visual-only, auditory-only and audiovisually. A broadband noise was mixed with the signal for the latter two conditions. The results revealed a significant three-way interaction of talker, speaking style and perceptual modality. Post-hoc analyses revealed intra and interspeaker differences in speech intelligibility for both speaking styles, in all three perceptual modalities. Overall, positive clear speech effects were observed in all three modalities. Intermodality comparisons revealed differences in the pattern of clear speech effects displayed by individual talkers. This finding indicates that there is not a direct association between the beneficial effects of clear speech in one perceptual modality and its effects on speech intelligibility in another perceptual modality.

Providing an internet-based audiological counselling programme to new hearing aid users: A qualitative study

People with an acquired hearing loss often have difficulty adjusting to a first hearing aid. Studies have shown that audiological counselling can facilitate adjustment to a first hearing aid. Because of its interactive nature, the internet could be a valuable tool to gain information about the experiences of the new hearing aid user and to address the needs for audiological counselling. An internet-based audiological counselling programme in the form of daily e-mails during the first month after the hearing aid fitting was offered to three new hearing aid users. The data, qualitative in nature, were comprised of the content of the e-mails and of in-depth interviews with the participants and their audiologist, and were analysed according to grounded theory. Overall, the internet-based audiological counselling programme provided rich descriptions of the experiences of the participants and reinforced positive adjustment behaviours experienced by them.

Estimation of dissolved organic carbon (DOC) concentrations in nanoliter samples using UV spectroscopy.

A simple analytical system has been developed and tested for estimating dissolved organic carbon (DOC) concentrations in nanoliter samples of sediment porewaters. The system consists of a loop injector that introduces 200 nL of sample directly into the capillary tubing connected to a scanning UV-VIS detector equipped with a 35-nanoliter capillary flowcell. Analysis of DOC by spectroscopic and high-temperature catalytic oxidation (HTCO) methods on the same samples showed a strong linear correlation between UV absorbance at 254 nm and HTCO-DOC concentration, allowing the DOC quantification. The simplicity and the robustness of the UV system allow DOC measurements in the field at a rate of 30 samples/h. We have used the UV system successfully for determining high-resolution distributions of porewater DOC concentrations in sediments at millimeter scales.