Unsuccessful Users Research Articles

KONSTRUKCJA I ROZWÓJ IMPLANTU VIBRANT SOUNDBRIDGE Z PERSPEKTYWY 25 LAT

The Vibrant Soundbridge is a semi-implantable “direct drive” hearing system for the treatment of hearing loss. People who are unsuccessful users of acoustic hearing aids or who are dissatisfied with their hearing aids have been successfully fitted with the device. The Vibrant Soundbridge is comprised of an external audio processor and an internal vibrating ossicular prosthesis, which together convert environmental sound into a vibratory signal delivered to the inner ear. This unique middle ear implant system has, over the past 25 years, proven to be an effective solution for many types of hearing loss – mild to severe sensorineural hearing loss, as well as for conductive or mixed hearing loss. This review gives an overview of the design and development of the system, with a focus on its biomechanics, over the last 25 years.

N400 and short speech stimuli

ABSTRACT In some children who have cochlear implants (CI), the expected speech-language outcome is not achieved despite fulfilment of requirements for its successful use. This may be attributed to processing difficulties at higher levels of the auditory pathway. The aim of this study was to investigate the processing of speech stimuli at the auditory-cortex level in 20 children aged 8 to 10 years who have a hearing impairment and have been using cochlear implants, by means of cortical auditory evoked potentials (CAEP). The children were divided into two groups, depending on the outcome: 10 successful implant users and 10 unsuccessful implant users, whose speech-language development has not progressed as expected. The control group comprised of 10 age-matched children with typical hearing and speech-language development. Two double consonant+vowel syllables (CVCV) were used as stimuli, presented in an oddball paradigm that required the subjects to react consciously. Latencies and amplitudes of CAEP waves were measured. In addition to the waves that typically occur in CAEP and reflect auditory processing at the level of the auditory cortex, N400 wave (associated with semantic processing) was recorded in the normally hearing group and successful CI users, but not in the unsuccessful CI users. Additionally, successful CI users and controls had comparable latencies of the P300 wave (preceding the N400) as well. Although P300 and N400 reflect two processes, they are related so that if P300 does not reach the expected amplitude and latency, neither will N400.

Analysis and Design of SCMA-Based Hybrid Unicast-Multicast Relay-Assisted Networks.

This paper studies a multi-user network model based on sparse code multiple access (SCMA), where both unicast and multicast services are considered. In the direct transmission scheme, the communication between the base station (BS) and the users is completed with one stage, in which the relay is inexistent. In the two-stage cooperative transmission scheme, any number of relays are placed to improve the reliability of wireless communication system. The BS broadcasts the requested message to users and relays in the first stage, and the successful relays forward the message to unsuccessful users in the second stage. To characterize the performance of these two schemes, we derive the exact and approximate expressions of average outage probability. Furthermore, to take full advantage of the cooperative diversity, an optimal power allocation and relay location strategy in the high signal-to-noise ratio (SNR) regime is studied. The outage probability reaches the minimum value when the first stage occupies half of the total energy consumed. Simulation and analysis results are presented to demonstrate the performance of these two schemes. The results show that the two-stage cooperative scheme effectively reduce the average outage probability in SCMA network, especially in the high SNR region.

When running fast is not the best option: failure of user involvement in design development processes

This paper analyses barriers to user involvement in design development by focusing on a failure case. By conducting a single-case study on a freelance designer and his client, we found that an accelerated speed of development was among the most important factors that negatively influenced the development of creative concepts, including the final product. This accelerated speed of development limited the time allocated to user involvement and impacted both the product-client fit and the artistic value that makes creative products relevant or appealing in the first place. Specifically, this paper contributes to the scholarship on the failure of user involvement by analysing an actor (a freelancer) with very limited resources. In addition, this paper extends our understanding about the formation of the outcome of user involvement: the final product. From a managerial perspective, this paper serves as a warning about the drawbacks of adopting accelerated product development and provides guidance on how to avoid unsuccessful user involvement.

Upper airway stimulation therapy: A novel approach to managing obstructive sleep apnea.

Review the role of upper airway stimulation (UAS) therapy in the management of moderate to severe obstructive sleep apnea (OSA). A literature search was performed of PubMed and Medline using the search terms clinical trial; obstructive sleep apnea; upper airway stimulation; hypoglossal stimulation; hypoglossal nerve; Inspire; and ImThera. All published clinical trials of currently available devices were reviewed. Unpublished data were excluded. UAS therapy results in surgical success (AHI decrease of >50% and overall AHI <= 20) in 66% of implanted subjects. In addition, UAS therapy results in significant improvement in daytime sleepiness, snoring, and sleep-related quality of life. UAS therapy is a valid alternative for select patients with moderate to severe OSA who are unsuccessful users of CPAP therapy. Laryngoscope, 126:S5-S8, 2016.

Cooperative Wireless Multicast: Performance Analysis and Time Allocation

Cooperative wireless multicast is investigated, in which a source sends multicast messages to a number of users. For a multicast message from the source, some users do not successfully receive the message (called unsuccessful users). For a successful user (who successfully receives the message from the source), we define its worst relaying channel gain as the smallest channel gain among its channel gains to all unsuccessful users. It is proposed that the successful user whose worst relaying channel gain is the highest among the worst relaying channel gains of all successful users is selected to serve as a relay. Considering that the channels in the system are independent but nonidentically distributed Rayleigh fading, we derive a closed-form outage probability expression for the proposed scheme. It is shown that the proposed scheme can achieve full diversity, and thus, having a larger number of users can improve the outage performance. Furthermore, we study the time allocation strategy that determines the durations used by the source and the selected relay for their transmissions, respectively. An approximate optimal time allocation is derived. In addition, we also investigate the case with relay selection error and the case with mixed Rayleigh/Rician fading. Simulation results verify the performance of the proposed cooperative multicast scheme and time allocation strategy.

Predicting three-month and 12-month post-fitting real-world hearing-aid outcome using pre-fitting acceptable noise level (ANL)

Objective: Determine the extent to which pre-fitting acceptable noise level (ANL), with or without other predictors such as hearing-aid experience, can predict real-world hearing-aid outcomes at three and 12 months post-fitting. Design: ANLs were measured before hearing-aid fitting. Post-fitting outcome was assessed using the international outcome inventory for hearing aids (IOI-HA) and a hearing-aid use questionnaire. Models that predicted outcomes (successful vs. unsuccessful) were built using logistic regression and several machine learning algorithms, and were evaluated using the cross-validation technique. Study sample: A total of 132 adults with hearing impairment. Results: The prediction accuracy of the models ranged from 61% to 68% (IOI-HA) and from 55% to 61% (hearing-aid use questionnaire). The models performed more poorly in predicting 12-month than three-month outcomes. The ANL cutoff between successful and unsuccessful users was higher for experienced (∼18 dB) than first-time hearing-aid users (∼10 dB), indicating that most experienced users will be predicted as successful users regardless of their ANLs. Conclusions: Pre-fitting ANL is more useful in predicting short-term (three months) hearing-aid outcomes for first-time users, as measured by the IOI-HA. The prediction accuracy was lower than the accuracy reported by some previous research that used a cross-sectional design.

The Benefits of Social Support for Listeners with Impaired Hearing

The Benefits of Social Support for Listeners with Impaired Hearing

On the pitfalls of bibliographic database searching: comparing successful and less successful users

This article investigates individual factors that determine success and failure in bibliographic database searching. In line with previous research, we hypothesised that the low usability of advanced bibliographic database interfaces (e.g. OvidSP™) would hinder students in implementing their information-seeking knowledge. Furthermore, we assumed high conscientiousness and need for cognitive closure to drive students towards rigidly using such advanced interfaces, even if they overtax them. In a study with 116 psychology undergraduates, 3 types of searchers were identified by means of a cluster analysis: successful database users, unsuccessful database users, and no-database users (e.g. Google Scholar™ searchers). Multiple regression revealed the relationship between information-seeking knowledge and search success to be positive for no-database users and negative for unsuccessful database users: unsuccessful database users do not only have trouble putting their information-seeking knowledge into practice; high information-seeking knowledge even impairs their search success, presumably because it makes them use advanced functions that they are not yet able to master. T-tests revealed that unsuccessful users differ from successful users in terms of higher conscientiousness and need for cognitive closure. In conclusion, our results highlight the importance of enhancing database interface usability and underline the crucial role of practical database instruction.

Indications and outcomes for use of Montgomery cannulas.

To our knowledge, we report the first series to analyze use of the Montgomery cannula as an airway management tool for indications other than obstructive sleep apnea. To analyze the use and outcomes of Montgomery cannula placement for airway management and to identify indications for placement. Retrospective review of 20 patients who received a Montgomery cannula from 2003 through 2012 at the University of Iowa Hospitals and Clinics. Montgomery cannula placement. Indications for cannula placement, comorbidities, body mass index, reasons for failure of cannula use, and complications. Indications included glottic stenosis (n = 7), obstructive sleep apnea (n = 5), bilateral vocal cord paralysis (n = 4), subglottic stenosis (n = 4), supraglottic swelling after radiation or chemoradiation therapy (n = 4), bulbar dystonia with paradoxical vocal cord motion (n = 1), vocal cord fixation secondary to rheumatoid arthritis and gastroesophageal reflux disease (n = 1), and airway obstruction associated with seizure disorder (n = 1). Comorbidities included obesity or overweight (n = 14), gastroesophageal reflux disease (n = 9), hypertension (n = 7), and diabetes mellitus (n = 6). Fifteen patients successfully used a Montgomery cannula, including all patients with 3 or fewer comorbidities. Five patients required replacement with a Jackson tracheostomy tube due to persistent tracheostomal granulation tissue (n = 2), feeling safer with the tracheostomy tube (n = 1), a posterior scar band causing airway obstruction (n = 1), and inability to care for the cannula because of poor manual dexterity from arthritis (n = 1). The mean (range) body mass index of successful and unsuccessful users was 27.5 (18.2-37.7) and 33.8 (24.1-42.7), respectively. Complications included the cannula being blocked by adipose tissue (n = 2) or pushed posteriorly into the airway (n = 2). The Montgomery cannula was used as a successful decannulation tool in 4 patients-with the cannula serving as an interim airway management tool leading to tracheostome closure. We identified features associated with successful use of the cannula and an additional indication for a Montgomery cannula as a step-down management tool for decannulation.

Advantages of binaural amplification to acceptable noise level of directional hearing aid users.

ObjectivesThe goal of the present study was to examine whether Acceptable Noise Levels (ANLs) would be lower (greater acceptance of noise) in binaural listening than in monaural listening condition and also whether meaningfulness of background speech noise would affect ANLs for directional microphone hearing aid users. In addition, any relationships between the individual binaural benefits on ANLs and the individuals' demographic information were investigated.MethodsFourteen hearing aid users (mean age, 64 years) participated for experimental testing. For the ANL calculation, listeners' most comfortable listening levels and background noise level were measured. Using Korean ANL material, ANLs of all participants were evaluated under monaural and binaural amplification with a counterbalanced order. The ANLs were also compared across five types of competing speech noises, consisting of 1- through 8-talker background speech maskers. Seven young normal-hearing listeners (mean age, 27 years) participated for the same measurements as a pilot testing.ResultsThe results demonstrated that directional hearing aid users accepted more noise (lower ANLs) with binaural amplification than with monaural amplification, regardless of the type of competing speech. When the background speech noise became more meaningful, hearing-impaired listeners accepted less amount of noise (higher ANLs), revealing that ANL is dependent on the intelligibility of the competing speech. The individuals' binaural advantages in ANLs were significantly greater for the listeners with longer experience of hearing aids, yet not related to their age or hearing thresholds.ConclusionBinaural directional microphone processing allowed hearing aid users to accept a greater amount of background noise, which may in turn improve listeners' hearing aid success. Informational masking substantially influenced background noise acceptance. Given a significant association between ANLs and duration of hearing aid usage, ANL measurement can be useful for clinical counseling of binaural hearing aid candidates or unsuccessful users.

Wireless Multicast Using Relays: Incentive Mechanism and Analysis

In wireless multicast systems, cooperative multicast, in which successful users help to relay received packets to unsuccessful users, has been shown to be effective in combating channel fading and improving system performance. However, this mechanism requires the users' voluntary contributions, which cannot be guaranteed since users are selfish and only care about their own performance. Furthermore, users may have heterogeneous costs (which are their private information) to forward packets, and they may lie about their costs if cheating can improve their utilities. To address these problems, in this paper, we model the interaction among users in the wireless multicast system as a multiseller multibuyer payment-based game, where users pay to receive relay service and get paid if they forward packets to others. A simplified case with homogeneous users that have the same cost to forward packets is investigated first. Then, for the case with heterogeneous users, to encourage users to tell their true costs, we use the second-price sealed-bid auction, which is a truth-telling auction, since bidding the true cost is a weakly dominant strategy. To analyze the multiseller multibuyer payment-based game, we observe that under different selected prices, the game can converge to different equilibria, resulting in different user free-riding probabilities and system throughput. We also study the price selection problem and derive the optimal price that maximizes the system throughput. Simulation results show the effectiveness of our proposed mechanism.

Successful and unsuccessful users of bilateral amplification: Differences and similarities in binaural performance

Bilateral amplification seems to be the best solution for bilaterally hearing-impaired persons. Nevertheless, some individuals are unsuccessful with this strategy. The goals of the present study were to develop tests to improve the diagnostic test battery before rehabilitation of hearing-impaired persons with bilateral or unilateral amplification, and to evaluate the tests with normally-hearing subjects and with two groups of hearing-impaired persons. The latter two groups contained 11 successful and 11 unsuccessful users of bilateral amplification respectively. Hearing thresholds, speech recognition in noise, signal analysis ability, binaural abilities, and dichotic tests were used in the investigation. The subjects answered a questionnaire and hearing aid gain curves were measured. The results for the two groups were similar for peripheral hearing functions and binaural performance. The unilateral amplification group showed significantly worse results in speech-in-noise and dichotic tests. Spatial aspects within the questionnaire were correlated to amplification preference. We therefore suggest the inclusion of speech-in-noise, dichotic tests, and questions on spatial orientation into the diagnostic scheme before rehabilitation with hearing aids.SumarioLa amplificación bilateral parece ser la mejor solución para las personas con daño auditivo bilateral. Sin embargo, algunos individuos no tienen éxito con esta estrategia. Las metas del presente estudio fueron desarrollar pruebas para mejorar la batería diagnósticas de exámenes antes de la rehabilitación de personas hipoacúsicas con amplificación unilateral o bilateral, y evaluar las pruebas en personas con audición normal, y con dos grupos de personas con daño auditivo. Los últimos dos grupos incluían 11 usuarios exitosos y 11 usuarios no exitosos de amplificación bilateral, respectivamente. Se utilizaron en esta investigación umbrales auditivos, reconocimiento de lenguaje en ruido, capacidad de análisis de la señal, capacidades binaurales y pruebas dicóticas. Los sujetos contestaron un cuestionario y se midieron las curvas de ganancia para auxiliares auditivos. Los resultados para los dos grupos fueron similares para las funciones auditivas periféricas y para el desempeño binaural. El grupo de amplificación unilateral mostró resultados significativamente peores en las pruebas dicóticas y de lenguaje en ruido. Los aspectos espaciales dentro del cuestionario se correlacionaron con las preferencias en la amplificación. Sugerimos, por tanto, la inclusión de pruebas dicóticas, de lenguaje en ruido y preguntas sobre orientación espacial en el esquema diagnóstico antes de la rehabilitación con auxiliares auditivos.

Crisp bags, one-dimensional fuzzy bags, multidimensional fuzzy bags: Comparing successful and unsuccessful user's Web behavior

In all studies of user's behavior on searching the Web, researchers found that their search strategy or traversal process showed a pattern of moving back and forth between searching and browsing. These activities of searching and browsing are inclusive activities to complete a goal-oriented task to find the answer for the query. The moving back and forth, including backtracking to a former Web page, constitutes the measurable or physical states or actions that a user takes while searching the Web. How do we account for the repeated searching and browsing and shifting between different Web pages to better understand the behavior of users? Is there a mathematical model that can help model actions of users to distinguish between two users while their repeated actions are accounted for since it is a part of their behavior or inherent essence to arrive at the goal of answering the questions regardless whether they are successful or unsuccessful? The idea of a set does not help account for repeated actions since in a set repeated objects are ignored. In some situations, we want a structure in which a collections of objects in the same sense as a set but a redundancy counts. The structure of a bag as a framework can help study the behavior of users and uncover some intrinsic properties about users. Also would bags help distinguish between two sets of users based on their syntactic properties without a priori knowledge of their semantic properties? This study constitutes a premier in applying bags to user's mining of the Web. The research will consider queries that depend on one variable or “univariable.” An example of “univariable” queries is “Find the number of Web pages of users whose searching is less than the average.” Crisp bags failed to answer such a query. Fuzzy operators were used successfully in comparing the “fuzzy bag” of the successful users to the “fuzzy bag” of unsuccessful users to answer such a query. A distance between two fuzzy bags was also established. The research also considered queries that depend on more than one variable or multivariable. An example of a “multivariable” query is “Find the number of Web pages of users whose number of searches is less than average and hyperlink navigation is less than the average.” One-dimensional fuzzy bags were extended to two-dimensional fuzzy bags and two-dimensional fuzzy bag operators were used to answer such a query. © 2009 Wiley Periodicals, Inc.

Compliance, quality of life and quantitative voice quality aspects of hands-free speech

ConclusionsWith the use of a new automatic stoma valve (ASV) it appears possible to rehabilitate patients who have previously been unsuccessful in acquiring hands-free speech. As well as making daily ASV use possible for an additional group of patients, this new device was also appreciated by many patients as an additional rehabilitation tool for specific occasions. Despite statistically significant improvements in aspects of voice and breathing using this novel ASV, improvement of peristomal adhesion is probably the main factor needed to further increase success rates. Nevertheless, our results show that it makes sense to keep trying to achieve hands-free speech, even if previous attempts have failed.ObjectiveTo make a long-term (6 months) assessment of compliance and aspects of voice, breathing and quality of life using a new ASV: the Provox FreeHands heat and moisture exchanger (HME).Material and methodsThis was a prospective clinical multicentre trial in 79 laryngectomized patients (8 regular ASV users, 58 previously unsuccessful users and 13 new users). Data were collected at baseline and after 1 and 6 months by means of European Organization for Research and Treatment of Cancer Quality of Life questionnaires and specific structured questionnaires concerning compliance, skin adhesion, voicing and pulmonary aspects. An objective assessment of voice parameters (maximum phonation time, maximum phonation time while counting, dynamic loudness range and number of pauses in a standard read-aloud text) was made for comparison of different stoma occlusion methods (digital occlusion via an HME and two different ASVs). A subjective assessment of overall voice quality was made.ResultsAfter 6 months, 19% of patients used the new ASV on a daily basis (mean 5 h/day), while 57% used it on an irregular basis as an additional rehabilitation tool for special occasions. Two-thirds of the study group indicated that they would continue to use the new ASV after the study period. With respect to the objective parameters, statistically significantly better maximum phonation times and dynamic loudness ranges were observed with the new ASV compared to the Blom–Singer ASV. However, the best results for all the objective parameters were obtained with digital occlusion via the Provox HME.

Relationship between Laboratory Measures of Directional Advantage and Everyday Success with Directional Microphone Hearing Aids

The improvement in speech recognition in noise obtained with directional microphones compared to omnidirectional microphones is referred to as the directional advantage. Laboratory studies have revealed substantial differences in the magnitude of the directional advantage across hearing-impaired listeners. This investigation examined whether persons who were successful users of directional microphone hearing aids in everyday living tended to obtain a larger directional advantage in the test booth than persons who were unsuccessful users. Results revealed that the mean directional advantage did not differ significantly between patients who used the directional mode regularly and those who reported little or no benefit from directional microphones in daily living and, therefore, tended to leave their hearing aids set in the default omnidirectional mode. Success with directional microphone hearing aids in everyday living, therefore, cannot be reliably predicted by the magnitude of the directional advantage obtained in the clinic.

Imaging ability and effective use of guided imagery.

Imaging ability, the ability to generate mental images and become absorbed in them as if they were real, is proposed as a moderator in the relationship between guided imagery and symptom relief. Two existing measures of image generation, Marks's (1973) Vividness of Visual Imagery Questionnaire and Betts's (1909) shortened Questionnaire Upon Mental Imagery (Sheehan, 1967), and one measure of absorption, Tellegen's Absorption scale (1993; TAS) were completed by 60 graduate students prior to listening to a guided imagery intervention to relieve anxiety associated with an upcoming stressful task. Analyses were conducted using data from 30 participants (7 men and 23 women) who reported an increase in anxiety level after learning of the stressful task. Participants were divided into two groups, successful (n=21) and unsuccessful (n=9) users of imagery, based on change in anxiety scores after listening to the guided imagery intervention. Absorption (TAS) scores were significantly higher for persons in the successful group; there were no differences in image generation scores. Two TAS items were identified as potential predictors of success with guided imagery. Findings may be helpful in developing a clinically useful instrument to predict likelihood of success with guided imagery in relieving cancer pain and its distress.

The clinical effectiveness of contraceptive methods

The clinical effectiveness of contraceptive methods is examined. The history of the measurement of clinical effectiveness is presented from early use of the percentage of successful and unsuccessful users Pearls method of pregnancy rate per 100 years of exposure to the Stix-Notestein method based on a ratio expressing the number of pregnancies prevented during a given period of exposure as a percentage of the number expected without contraception. Demographic data on the effectiveness of contraception in the general population was presented from a study of 2000 white Protestant couples interviewed in Indianapolis in 1941 and 1942. The pregnancy rates of the most widely used methods of contraception are presented. The pregnancy rate of the diaphragm was 4/100 years of exposure condom 7/100 years exposure withdrawal 10/100 years and douche 21/100 years. Great Britains pregnancy rate for a study done in 1946-1947 was 6/100 years for appliance methods and 8/100 years for nonappliance methods. The clinical effectiveness for widely used ocntraceptive methods taken from the literature is summarized. Lack of uniformity in methodology of data collection or differences in residence education and degree of motivation makes comparisons difficult for these data. Differences in acceptance of a particular contraceptive method are in large part responsible for differences in effectiveness between population groups. It is suggested that a more effective clinic service would be obtained by offering a variety of contraceptive methods from which to choose.