Co-Designing a Mobile-Based Game to Improve Misinformation Resistance and Vaccine Knowledge in Uganda, Kenya, and Rwanda.

Misinformation can decrease public confidence in vaccines, and reduce vaccination intent and uptake. One strategy for countering these negative impacts comes from inoculation theory. Similar to biological vaccination, inoculation theory posits that exposure to a weakened form of misinformation can develop cognitive immunity, reducing the likelihood of being misled. Online games offer an interactive, technology-driven, and scalable solution using an active form of inoculation that engages and incentivizes players to build resilience against misinformation. We document the development of the critical thinking game Cranky Uncle Vaccine. The game applies research findings from inoculation theory, critical thinking, humor in science communication, and serious games. The game content was iterated through a series of co-design workshops in Kampala (Uganda), Kitale (Kenya), and Kigali (Rwanda). Workshop participants offered feedback on cartoon character design, gameplay experience, and the game's content, helping to make the game more culturally relevant and avoid unintended consequences in East African countries. Our co-design methodology offers an approach for further adaptation of the Cranky Uncle Vaccine game to other regions, as well as a template for developing locally relevant interventions to counter future infodemics.

The HIV Cascade of Care and Service Utilisation at Sex Work Programmes Among Female Sex Workers in South Africa.

Female sex workers (FSWs) in South Africa experience a uniquely high prevalence of HIV. We describe the HIV cascade of care (CoC) in FSWs in South Africa, and explored service utilisation at sex work programmes. A cross-sectional, study enrolled FSWs across 12 sites in South Africa. Participants were recruited using chain-referral method. Inclusion criteria: ≥ 18 years, cis-gender female, sold/transacted in sex, HIV positive. 1862 HIV positive FSWs were enrolled. 92% were known positive, 87% were on antiretroviral treatment (ART). Of those on ART, 74% were virally suppressed. Younger FSWs were significantly less likely to be on ART or virally suppressed. Female sex workers using HIV services from specialised programs were 1.4 times more likely to be virally suppressed than non-program users. The pre-COVID-19 pandemic HIV CoC amongst FSWs in South Africa shows striking improvement from previous estimates, and approaches achievement of 90:90:90 goals.

Level of adult client satisfaction with clinic flow time and services of an integrated non-communicable disease-HIV testing services clinic in Soweto, South Africa: a cross-sectional study.

BACKGROUND: While HIV Testing Services (HTS) have increased, many South Africans have not been tested. Non-communicable diseases (NCDs) are the top cause of death worldwide. Integrated NCD-HTS could be a strategy to control both epidemics. Healthcare service strategies depends partially on positive user experience. We investigated client satisfaction of services and clinic flow time of an integrated NCD-HTS clinic. METHODS: This prospective, cross-sectional study evaluated HTS client satisfaction with an HTS clinic at two phases. Phase 1 (February-June 2018) utilised standard HTS services: counsellor-led height/weight/blood pressure measurements, HIV rapid testing, and symptoms screening for sexually transmitted infections/Tuberculosis. Phase 2 (June 2018-March 2019) further integrated counsellor-led obesity screening (body mass index/abdominal circumference measurements), rapid cholesterol/glucose testing; and nurse-led Chlamydia and human papilloma virus (HPV)/cervical cancer screening. Socio-demographics, proportion of repeat clients, clinic flow time, and client survey data (open/closed-ended questions using five-point Likert scale) are reported. Fisher's exact test, chi-square analysis, and Kruskal Wallis test conducted comparisons. Multiple linear regression determined predictors associated with clinic time. Content thematic analysis was conducted for free response data. RESULTS: Two hundred eighty-four and three hundred thirty-three participants were from Phase 1 and 2, respectively (N = 617). Phase 1 participants were significantly older (median age 36.5 (28.0-43.0) years vs. 31.0 (25.0-40.0) years; p = 0.0003), divorced/widowed (6.7%, [n = 19/282] vs. 2.4%, [n = 8/332]; p = 0.0091); had tertiary education (27.9%, [n = 79/283] vs. 20.1%, [n = 67/333]; p = 0.0234); and less female (53.9%, [n = 153/284] vs 67.6%, [n = 225/333]; p = 0.0005), compared to Phase 2. Phase 2 had 10.2% repeat clients (n = 34/333), and 97.9% (n = 320/327) were 'very satisfied' with integrated NCD-HTS, despite standard HTS having significantly shorter median time for counsellor-led HTS (36.5, interquartile range [IQR]: 31.0-45.0 vs. 41.5, IQR: 35.0-51.0; p < 0.0001). Phase 2 associations with longer clinic time were clients living together/married (est = 6.548; p = 0.0467), more tests conducted (est = 3.922; p < 0.0001), higher overall satisfaction score (est = 1.210; p = 0.0201). Those who matriculated experienced less clinic time (est = - 7.250; p = 0.0253). CONCLUSIONS: It is possible to integrate counsellor-led NCD rapid testing into standard HTS within historical HTS timeframes, yielding client satisfaction. Rapid cholesterol/glucose testing should be integrated into standard HTS. Research is required on the impact of cervical cancer/HPV screenings to HTS clinic flow to determine if it could be scaled up within the public sector.

The effect of tone-vocoding on spatial release from masking for old, hearing-impaired listeners.

Old, hearing-impaired listeners generally benefit little from lateral separation of multiple talkers when listening to one of them. This study aimed to determine how spatial release from masking (SRM) in such listeners is affected when the interaural time differences (ITDs) in the temporal fine structure (TFS) are manipulated by tone-vocoding (TVC) at the ears by a master hearing aid system. Word recall was compared, with and without TVC, when target and masker sentences from a closed set were played simultaneously from the front loudspeaker (co-located) and when the maskers were played 45° to the left and right of the listener (separated). For 20 hearing-impaired listeners aged 64 to 86, SRM was 3.7 dB smaller with TVC than without TVC. This difference in SRM correlated with mean audiometric thresholds below 1.5 kHz, even when monaural TFS sensitivity (discrimination of frequency-shifts in identically filtered complexes) was partialed out, suggesting that low-frequency audiometric thresholds may be a good indicator of candidacy for hearing aids that preserve ITDs. The TVC difference in SRM was not correlated with age, pure-tone ITD thresholds, nor fundamental frequency difference limens, and only with monaural TFS sensitivity before control for low-frequency audiometric thresholds.

Analysis of Prehospital Transport Use for Trauma Patients in Lusaka, Zambia.

Despite an increasing burden of injuries, prehospital transport systems remain underdeveloped in many low- and middle-income countries. Little information exists on the use of prehospital services for trauma patients in Zambia. METHOD: A prospective, observational study of trauma presentations was undertaken for 6 months in Lusaka, Zambia, to establish the epidemiology and outcomes of injury in the region. In addition to demographics and mechanism of injury, data were collected on prehospital transport as well as inpatient resources utilization. Trained study personnel gathered data on trauma presentations 24 h a day. Statistical analysis was conducted using SAS 9.3 from a Microsoft® Access database. RESULTS: 3498 trauma patients were enrolled in the study on arrival to University Teaching Hospital (UTH). 3264 patients had a transport means recorded (95.3 %). Two-thirds (66 %) arrived within 6 h of injury, and 23 % arrived within the first hour after injury. A majority arrived by private vehicle (53.4 %) or public transport (37.7 %); only 5.9 % were transported by public or private ambulance. Of those arriving within the first hour after injury, 69.1 % came by private car, 24.6 % by public transport and 3.1 % by ambulance. There was a small statistical increase in Kampala Trauma Score II among ambulance arrivals. CONCLUSION: Trauma patient use a variety of transport methods to get to UTH. A majority of patients use no formal ambulance transport. Despite this fact, a majority arrives within 6 h of injury but receive no formal prehospital care. An integrated, multilayered prehospital care and transport system may be the most effective approach for Zambia.

Diagnosis and management of depression in children and young people: summary of updated NICE guidance.

This is one of a series of BMJ summaries of new guidelines based on the best available evidence; they highlight important recommendations for clinical practice, especially where uncertainty or controversy exists.

Exposure to and experiences of violence among adolescents in lower socio-economic groups in Johannesburg, South Africa.

BACKGROUND: We explored exposure to and experiences of violence and their risk factors amongst ethnically diverse adolescents from lower socio economic groups in Johannesburg. METHODS: This cross-sectional study recruited a stratified sample of 16-18 year old adolescents from four low socio-economic suburbs in Johannesburg to reflect ethnic group clustering. We collected socio-demographic, sexual behaviour, alcohol and drug use and trauma events data. Proportions and risk factors were assessed by chi-square and logistic regression. RESULTS: Of 822 adolescents, 57% (n = 469) were female. Approximately 62% (n = 506) were Black, 13% (n = 107) Coloured, 13% (n = 106) Indian and 13% (n = 103) White. Approximately 67% (n = 552) witnessed violence to a non-family member, 28% (n = 228) experienced violence by a non-family member, and 10% (n = 83) reported sexual abuse. Multivariate analysis determined that witnessing violence in the community was associated with being Black (OR: 4.6, 95%CI: 2.7-7.9), Coloured (OR: 3.9, 95%CI: 2.0-7.4) or White (OR: 8.0, 95%CI:4.0-16.2), repeating a grade (OR: 1.5, 95%CI: 1.01-2.1), having more than one sexual partner (OR: 1.7, 95%CI: 1.1-2.5) and ever taking alcohol (OR: 2.1, 95%CI: 1.5-2.9). Witnessing violence in the family was associated with being female (OR: 1.8, 95%CI: 1.3-2.6), being Black (OR: 2.2, 95%CI: 1.1-4.1), or White (OR: 3.0, 95%CI: 1.4-6.4), repeating a grade (OR: 1.6, 95%CI: 1.1-2.2) and ever taking alcohol (OR: 2.9, 95%CI: 2.0-4.3). CONCLUSIONS: In low socio-economic areas in Johannesburg, Black, White and Coloured adolescents experience a high burden of violence. Interventions to mitigate the effects of violence are urgently required.

The role of excitation-pattern cues in the detection of frequency shifts in bandpass-filtered complex tones.

One task intended to measure sensitivity to temporal fine structure (TFS) involves the discrimination of a harmonic complex tone from a tone in which all harmonics are shifted upwards by the same amount in hertz. Both tones are passed through a fixed bandpass filter centered on the high harmonics to reduce the availability of excitation-pattern cues and a background noise is used to mask combination tones. The role of frequency selectivity in this "TFS1" task was investigated by varying level. Experiment 1 showed that listeners performed more poorly at a high level than at a low level. Experiment 2 included intermediate levels and showed that performance deteriorated for levels above about 57 dB sound pressure level. Experiment 3 estimated the magnitude of excitation-pattern cues from the variation in forward masking of a pure tone as a function of frequency shift in the complex tones. There was negligible variation, except for the lowest level used. The results indicate that the changes in excitation level at threshold for the TFS1 task would be too small to be usable. The results are consistent with the TFS1 task being performed using TFS cues, and with frequency selectivity having an indirect effect on performance via its influence on TFS cues.

The effects of age and hearing loss on interaural phase difference discrimination.

The discrimination of interaural phase differences (IPDs) requires accurate binaural temporal processing and has been used as a measure of sensitivity to temporal envelope and temporal fine structure (TFS). Previous studies found that TFS-IPD discrimination declined with age and with sensorineural hearing loss (SNHL), but age and SNHL have often been confounded. The aim of this study was to determine the independent contributions of age and SNHL to TFS and envelope IPD discrimination by using a sample of adults with a wide range of ages and SNHL. A two-interval, two-alternative forced-choice procedure was used to measure IPD discrimination thresholds for 20-Hz amplitude-modulated tones with carrier frequencies of 250 or 500 Hz when the IPD was in either the stimulus envelope or TFS. There were positive correlations between absolute thresholds and TFS-IPD thresholds, but not envelope-IPD thresholds, when age was accounted for. This supports the idea that SNHL affects TFS processing independently to age. Age was positively correlated with envelope-IPD thresholds at both carrier frequencies and TFS-IPD thresholds at 500 Hz, when absolute thresholds were accounted for. These results suggest that age negatively affects the binaural processing of envelope and TFS at some frequencies independently of SNHL.

Benefit from non-linear frequency compression hearing aids in a clinical setting: the effects of duration of experience and severity of high-frequency hearing loss.

OBJECTIVES: To determine whether non-linear frequency compression (NLFC) is effective for hearing-impaired adults in a clinical setting. To determine whether benefit from NLFC is related to duration of NLFC experience or severity of high-frequency hearing loss. DESIGN: Participants were fitted with Phonak frequency compression hearing aids as part of their standard clinical care, using the manufacturer's default fitting settings. Participants had been using NLFC for between 1 and 121 weeks at the time of testing. Speech recognition thresholds in noise and consonant recognition in quiet were measured with and without NLFC enabled. STUDY SAMPLE: Forty-six experienced adult hearing-aid users. RESULTS: Consonant recognition in quiet, but not speech recognition in noise was significantly better with NLFC enabled. There was no significant correlation between duration of frequency compression experience and benefit. Benefit for consonant recognition was negatively correlated with mean audiometric thresholds from 2-6 kHz. CONCLUSIONS: NLFC was beneficial for consonant recognition but not speech recognition in noise. There was no evidence to support the idea that a long period of acclimatization is necessary to gain full benefit. The relation between benefit and high-frequency thresholds might be explained by the poor audibility of compressed information for some listeners with severe loss.

The second annual Vaccination Acceptance Research Network Conference (VARN2023): Shifting the immunization narrative to center equity and community expertise.

Promoting vaccine acceptance and demand is an essential, yet often underrecognized component of ensuring that everyone has access to the full benefits of immunization. Convened by the Sabin Vaccine Institute, the Vaccination Acceptance Research Network (VARN) is a global network of multidisciplinary stakeholders driving strengthened vaccination acceptance, demand, and delivery. VARN works to advance and apply social and behavioral science insights, research, and expertise to the challenges and opportunities facing vaccination decision-makers. The second annual VARN conference, When Communities Lead, Global Immunization Succeeds, was held June 13-15, 2023, in Bangkok, Thailand. VARN2023 provided a space for the exploration and dissemination of a growing body of evidence, knowledge, and practice for driving action across the vaccination acceptance, demand, and delivery ecosystem. VARN2023 was co-convened by Sabin and UNICEF and co-sponsored by Gavi, the Vaccine Alliance. VARN2023 brought together 231 global, regional, national, sub-national, and community-level representatives from 47 countries. The conference provided a forum to share learnings and solutions from work conducted across 40+ countries. This article is a synthesis of evidence-based insights from the VARN2023 Conference within four key recommendations: (1) Make vaccine equity and inclusion central to programming to improve vaccine confidence, demand, and delivery; (2) Prioritize communities in immunization service delivery through people-centered approaches and tools that amplify community needs to policymakers, build trust, and combat misinformation; (3) Encourage innovative community-centric solutions for improved routine immunization coverage; and (4) Strengthen vaccination across the life course through building vaccine demand, service integration, and improving the immunization service experience. Insights from VARN can be applied to positively impact vaccination acceptance, demand, and uptake around the world.

Knowledge, attitudes, and practices of vaccinators about expanded programs on immunization: a cross-sectional study.

Introduction: The periodic evaluation of knowledge, attitudes, and practices (KAP) of healthcare workers, including vaccinators, concerning expanded programs on immunization (EPI) is very crucial for a better healthcare system. This study was carried out to assess the KAP of vaccinators about the EPI, including cold storage of vaccines and their practices related to vaccine cold chain management. Method: A cross-sectional study was conducted from January 2022 to June 2022 among registered vaccinators in the twin cities (Islamabad and Rawalpindi) of Pakistan. A structured self-administered questionnaire (English and Urdu) was developed as per the Pakistan national EPI policy and strategic guidelines 2022 and World Health Organization (WHO) guidelines, as well as from earlier studies (Cronbach's alpha value of 0.734). The final questionnaire consisted of closed-ended questions in four sections, including sociodemographic information, knowledge (with dichotomous variables of yes/no), attitudes (with a 5-point Likert scale ranging from strongly agree to strongly disagree), and handling of vaccines and cold chain management. Completed questionnaires were entered into Microsoft Excel and then imported into SPSS version 25 for statistical analysis. Results: A total of 186 vaccinators completely filled out their questionnaires, with a 97.9% response rate. More than half of the participants (57.5%) had no training related to EPI. Most of the respondents had a moderate to poor level of knowledge regarding EPI. The overall attitude was positive, and 57% of the participants strongly agreed that the national immunization programs can significantly contribute to the decrease in morbidity and mortality rates among children. In the current study, participants showed good practices toward EPI, vaccine storage, and cold chain management. The majority (93.5%) of the participants checked the expiry of vaccines at regular intervals to maintain the first expiry first out (FEFO) in their healthcare setting. Discussion: In conclusion, most of the vaccinators had moderate to poor knowledge, a positive attitude, and good practices toward EPI, vaccine cold storage, and cold chain management. Lack of training among vaccinators on EPI was also observed. These findings have suggested that continuous training, education, and regular supervision of vaccinators in EPI are important for maximum immunization effectiveness and coverage.

Building a way forward: Enabling community voices to forge the path toward successful immunization for all.

Community engagement is vital to the development of people-centered, successful vaccination programs. The diverse Vaccination Acceptance Research Network (VARN) community brings together interdisciplinary professionals from across the immunization ecosystem who play a crucial role in vaccination acceptance, demand, and delivery. Over the course of the VARN2023 conference, researchers and practitioners alike shared ideas and experiences focused on strategies and approaches to building trust between communities and health systems to increase equity in vaccination. Health professionals and community members must have equal value in the design and delivery of community-centered immunization services, while key vaccination decision-makers must also consider community experiences, concerns, and expertise in program design and policymaking. Therefore, strategies for community engagement and cultivating trust with communities are crucial for the success of any immunization program. Furthermore, health workers need additional skills, support, and resources to effectively communicate complex information about immunization, including effective strategies for countering misinformation. This article summarizes three skills-building sessions offered at the VARN2023 conference, focused on human-centered design, motivational interviewing, and engaging with journalists to leverage the voices of communities. These sessions offered practical, evidence-based tools for use across geographic and social settings that can be used by practitioners, researchers, and other stakeholders to increase vaccination demand and uptake in their communities.

Differences in short-term training for interaural phase difference discrimination between two different forced-choice paradigms.

Improvement in interaural phase difference (IPD) discrimination over 2 to 3 h was compared for two two-alternative forced-choice paradigms: A three-interval paradigm, in which the IPD was in interval two or three, and a paradigm with two intervals of four stimuli in which the IPD was in the second and fourth stimuli of one interval (AAAA vs ABAB). The difference in performance between the beginning and end of the testing period was smaller for the two-interval paradigm, supporting the use of this paradigm for fast measurement of discrimination thresholds without the need for a long period of training.

Pandemic disruptions in vaccine uptake in a low-income setting: a qualitative inquiry.

BACKGROUND: While the COVID-19 pandemic has exposed the vulnerabilities of immunization delivery systems globally, the devastating impact of the pandemic on immunization delivery is most pronounced in low and middle-income countries like Pakistan. We conducted a qualitative study to capture the views and experiences of parents and healthcare workers (HWs) and assess the impact of the COVID-19 pandemic on childhood routine immunization (CRI) and COVID-19 vaccination in Pakistan. METHODS: We used a qualitative research design with a purposive sampling approach. Semi-structured interviews (via telephone) and focus group discussions (via Zoom) were conducted with parents/child caregivers and HWs, respectively. All qualitative interviews were conducted between February and July 2021 from three sites (two urban and one rural) in Sindh, Pakistan. Interviews were audio-recorded, transcribed, and coded for a team-based thematic analysis. RESULTS: Overall, most parents and HWs indicated a strong trust in the benefits of CRI; nonetheless, a substantial disruption in the delivery and uptake of these services was also reported. The barriers towards CRI included closed vaccination centers, drastic reduction in outreach programs, lack of information for parents/child caregivers on vaccine availability, fear in the community regarding vaccine safety, limited vaccine supply, and a lack of healthcare staff. For COVID-19 vaccines, challenges cited included skepticism about the reality of the pandemic and confusion over COVID-19 vaccines due to conflicting (or mis-or-dis) information. Both participant groups showed a willingness to integrate COVID-19 vaccination into Pakistan's Expanded Program for Immunization if required in the future. CONCLUSION: During the COVID-19 pandemic, disruptions of regular immunization delivery in Pakistan were not due to parental unwillingness to vaccinate, but rather to social and logistical challenges caused by a rapidly changing context and difficulties in providing vaccination services safely. Barriers to vaccine access and concerns about COVID-19 exposure during clinic visits also contributed to uncertainty regarding immunization services early in the pandemic. For catchup campaigns and future pandemics, more than focusing interventions on persuading people, strategic approaches to building resilience through system-based interventions, such as investing in surge capacity in the immunization workforce to bounce back quickly after the first shock are required.

Community-Based Approaches to Increase COVID-19 Vaccine Uptake and Demand: Lessons Learned from Four UNICEF-Supported Interventions.

Vaccination is critical to minimize serious illness and death from COVID-19. Yet uptake of COVID-19 vaccines remains highly variable, particularly among marginalized communities. This article shares lessons learned from four UNICEF interventions that supported Governments to generate acceptance and demand for COVID-19 vaccines in Zambia, Iraq, Ghana, and India. In Zambia, community rapid assessment provided invaluable real-time insights around COVID-19 vaccination and allowed the identification of population segments that share beliefs and motivations regarding COVID-19 vaccination. Findings were subsequently used to develop recommendations tailored to the different personas. In Iraq, a new outreach approach (3iS: Intensification of Integrated Immunization) utilized direct community engagement to deliver health messages and encourage service uptake, resulting in over 4.4 million doses of COVID-19 and routine immunization vaccines delivered in just 8 months. In Ghana, a human-centered design initiative was applied to co-develop community-informed strategies to improve COVID-19 vaccination rates. In India, a risk communication and community engagement initiative reached half a million people over six months, translating into a 25% increase in vaccination rates. These shared approaches can be leveraged to improve COVID-19 vaccination coverage and close gaps in routine immunization across diverse and marginalized communities.

Shaping global vaccine acceptance with localized knowledge: a report from the inaugural VARN2022 conference.

The first conference of the Vaccination Acceptance Research Network, VARN2022: Shaping Global Vaccine Acceptance with Localized Knowledge, was held virtually, from March 1st to 3rd 2022. This inaugural event brought together a global representation of experts to discuss key priorities and opportunities emerging across the ecosystem of vaccine acceptance and demand, from policies to programs and practice. Convened by the Sabin Vaccine Institute, VARN aims to support dialogue among multidisciplinary stakeholders to enhance the uptake of social and behavioral science-based solutions for vaccination decision-makers and implementers. The conference centered around four key themes: 1) Understanding vaccine acceptance and its drivers; 2) One size does not fit all: community- and context-specific approaches to increase vaccine acceptance and demand; 3) Fighting the infodemic and harnessing social media for good; and 4) Frameworks, data integrity and evaluation of best practices. Across the conference, presenters and participants considered the drivers of and strategies to increase vaccine acceptance and demand relating to COVID-19 vaccination and other vaccines across the life-course and across low-, middle- and high-income settings. VARN2022 provided a wealth of evidence from around the world, highlighting the need for human-centered, multi-sectoral and transdisciplinary approaches to improve vaccine acceptance and demand. This report summarizes insights from the diverse presentations and discussions held at VARN2022, which will form a roadmap for future research, policy making, and interventions to improve vaccine acceptance and demand globally.

Effect of speech material on the benefit of temporal fine structure information in speech for young normal-hearing and older hearing-impaired participants.

OBJECTIVE: The purpose of this study was to investigate the influence of the type of speech material on the benefit obtained from temporal fine structure (TFS) information in speech for young normal-hearing (YNH) and older hearing-impaired (OHI) participants. DESIGN: The design was based on the work of . They measured the speech reception thresholds for a target talker in a background talker as a function of the frequency range over which TFS information was available. The signal was split into 32 channels, each with a bandwidth equal to the equivalent rectangular bandwidth of the "normal" auditory filter at the same center frequency. Above a cutoff (CO) channel, channels were vocoded and contained only temporal envelope information. Channels up to and including CO were not processed. Hopkins et al. found that, as CO was increased, speech reception thresholds decreased more for normal-hearing participants than for participants with cochlear hearing loss, suggesting that the latter were less able to use TFS information. We used the same design, but compared results when the target speech materials were open-set sentences, as used by Hopkins et al., and when they were more predictable sentences with a closed word set (Danish Dantale 2). RESULTS: With the open-set material, YNH listeners benefited more from TFS information than OHI listeners, replicating . For the YNH participants, the benefit of adding TFS was greater for the open-set material than for the closed-set material, while no difference in TFS benefit across speech materials was found for the OHI participants. CONCLUSIONS: The choice of speech material is important when assessing the benefit of TFS. Several factors may facilitate recognition in the absence of TFS cues, including small set size, predictable temporal structure of the target speech, and contextual effects. We speculate that TFS information is useful for reducing informational masking, by providing cues for the perceptual segregation of the target and background. When the target speech is highly predictable, informational masking may be minimal, rendering TFS cues unnecessary.

The effect of compression speed on intelligibility: simulated hearing-aid processing with and without original temporal fine structure information.

Hearing aids use amplitude compression to compensate for the effects of loudness recruitment. The compression speed that gives the best speech intelligibility varies among individuals. Moore [(2008). Trends Amplif. 12, 300-315] suggested that an individual's sensitivity to temporal fine structure (TFS) information may affect which compression speed gives most benefit. This hypothesis was tested using normal-hearing listeners with a simulated hearing loss. Sentences in a competing talker background were processed using multi-channel fast or slow compression followed by a simulation of threshold elevation and loudness recruitment. Signals were either tone vocoded with 1-ERB(N)-wide channels (where ERB(N) is the bandwidth of normal auditory filters) to remove the original TFS information, or not processed further. In a second experiment, signals were vocoded with either 1 - or 2-ERB(N)-wide channels, to test whether the available spectral detail affects the optimal compression speed. Intelligibility was significantly better for fast than slow compression regardless of vocoder channel bandwidth. The results suggest that the availability of original TFS or detailed spectral information does not affect the optimal compression speed. This conclusion is tentative, since while the vocoder processing removed the original TFS information, listeners may have used the altered TFS in the vocoded signals.

Binaural temporal fine structure sensitivity, cognitive function, and spatial speech recognition of hearing-impaired listeners (L).

The relationships between spatial speech recognition (SSR; the ability to understand speech in complex spatial environments), binaural temporal fine structure (TFS) sensitivity, and three cognitive tasks were assessed for 17 hearing-impaired listeners. Correlations were observed between SSR, TFS sensitivity, and two of the three cognitive tasks, which became non-significant when age effects were controlled for, suggesting that reduced TFS sensitivity and certain cognitive deficits may share a common age-related cause. The third cognitive measure was also significantly correlated with SSR, but not with TFS sensitivity or age, suggesting an independent non-age-related cause.