Trends in Amplification最新文献

Hearing instrument technology research is almost entirely focused on the projected needs of the consumer market in the developed world. However, two thirds of the world's population with hearing impairment live in developing countries and this proportion will increase in future, given present demographic trends. In developing regions, amplification and other hearing health needs may differ from those in industrialized nations, for cultural, health, or economic reasons. World Health Organization estimates indicate that at present only a small percentage of individuals in developing countries who are in need of amplification have access to hearing aid provision. New technologies, such as trainable hearing aids, advanced noise reduction algorithms, feedback reduction circuitry, nano coatings for hearing aid components, and innovative power options, may offer considerable potential benefits, both for individuals with hearing impairment in developing countries and for those who provide hearing health care services in these regions. This article considers the possible supporting role of innovative hearing instrument technologies in the provision of affordable hearing health care services in developing countries and highlights the need for research that considers the requirements of the majority of the world population in need of hearing instrument provision.

A self-fitting hearing aid has been proposed as a viable option to meet the need for rehabilitation in areas where audiology services are unreliable. A successful outcome with a self-fitting hearing aid pivots in part on the clarity of the instructions accompanying the device. The aims of this article are (a) to review the literature to determine features that should be incorporated into written health-care materials and factors to consider in the design process when developing written instructions for a target audience of older adults and (b) to apply this information to the development of a set of written instructions as the first step in self-fitting of a hearing aid, assembling four parts and inserting the aid into the ear. The method involved a literature review of published peer reviewed research. The literature revealed four steps in the development of written health-care materials: planning, design, assessment of suitability, and pilot testing. Best practice design principles for each step were applied in the development of instructions for how to assemble and insert a hearing aid. Separate booklets were developed for the left and right aids and the content of each consisted of simple line drawings accompanied by captions. The reading level was Grade 3.5 equivalent and the Flesch Reading Ease Score was 91.1 indicating that the materials were "very easy" to read. It is essential to follow best practice design principles when developing written health-care materials to motivate the reader, maximize comprehension, and increase the likelihood of successful application of the content.

The research on self-fitting hearing aids is reviewed using evidence-based principles. The evaluation begins with a definition of the research questions followed by a detailed search of the literature and then a review of the relevant studies. Four features of self-fitting hearing aids are reviewed: in-situ threshold measurement, whether an initial fitting prescribed using standard prescription formulae will approximate user preferences, outcomes with training of hearing aids for preferred responses, and assembly and use of the aids. There is at least good quality evidence suggesting that in-situ thresholds can be reliably obtained, that prescribed initial fittings approximate preferred responses, and that users are able to train the hearing aids and would prefer the trained responses. However, evidence on other outcomes and the ability of users to assemble and use such instruments is limited. Gaps in research with self-fitting hearing aids are identified.

The need for reliable access to hearing health care services is growing globally, particularly in developing countries and in remotely located, underserved regions in many parts of the developed world. Individuals with hearing loss in these areas are at a significant disadvantage due to the scarcity of local hearing health care professionals and the high cost of hearing aids. Current approaches to making hearing rehabilitation services more readily available to underserved populations include teleaudiology and the provision of amplification devices outside of the traditional provider-client relationship. Both strategies require access to such resources as dedicated equipment and/or specially trained staff. Another possible strategy is a self-fitting hearing aid, a personal amplification device that is equipped with an onboard tone generator to enable user-controlled, automated, in situ audiometry; an onboard prescription to determine the initial hearing aid settings; and a trainable algorithm to enable user-controlled fine-tuning. The device is thus assembled, fitted, and managed by the user without the need for audiological or computer support. This article details the self-fitting concept and its potential application in both developing and developed countries. Potential advantages and disadvantages of such a device are discussed, and considerations for further investigations into the concept are presented. Overall, the concept is considered technologically viable with the main challenges anticipated to be development of clear, simple user instructions and a delivery model that ensures reliable supplies of instant-fit ear tips and batteries.

A self-fitting hearing aid is a personal amplification device that is designed to be assembled, programmed, and fine-tuned by the user, without the need for additional equipment or professional support. A written description of the device was presented to 80 older adults with a hearing impairment, all of whom were residents of an urban area in a developed country. In response to a structured questionnaire, the majority of participants reported that the self-fitting hearing aid concept was a good idea (83%), would be of personal benefit (60%), and could be managed independently by the user (90%). Overall, half of the participant group agreed with all three statements. Two were uncertain about the concept, but none of the participants rejected it outright. There were no significant differences between the opinions of participants with previous hearing aid experience and those without. Participant responses to open-ended questions revealed that the main benefits of a self-fitting hearing aid were thought to be the ability to self-adjust the device's settings (reported by 33% of participants) and increased convenience (20% of participants). The main drawback, mentioned by 25% of participants, was a preference for professional guidance through the fitting process. These results suggest that the self-fitting hearing aid may present as an alternative product in developed countries for those users who prefer to be in control of the fitting process.

A self-fitting hearing aid, designed to be assembled and programmed without audiological or computer support, could bring amplification to millions of people in developing countries, who remain unaided due to the lack of a local, professional, audiological infrastructure. The ability to assemble and insert a hearing aid is fundamental to the successful use of a self-fitting device. In this study, the management of such tasks was investigated. Eighty older, urban-dwelling, hearing-impaired adults in a developed country were asked to follow a set of written, illustrated instructions to assemble two slim-fit behind-the-ear hearing aids. Participants were allowed to access assistance with the task from an accompanying partner. A range of personal and audiometric variables was measured through the use of structured questionnaires and standardized tests of health literacy, cognitive function, and manual dexterity. The results showed that 99% of participants were able to complete the hearing aid assembly task, either on their own or with assistance. Health literacy, or the ability to read and understand health-related text, and gender most strongly influenced participants' ability to complete the assembly task independently and accurately. Higher levels of health literacy were associated with an increased likelihood of independent and successful task completion. Male participants were more likely to complete the task on their own, while female participants were more likely to assemble the device without errors. The results of this study will inform future work regarding development of educational material for the self-fitting hearing aid as well as candidacy for such a device.

Stuart Gatehouse was one of the pioneers of cognitive hearing science. The ease of language understanding (ELU) model (Rönnberg) is one example of a cognitive hearing science model where the interplay between memory systems and signal processing is emphasized. The mismatch notion is central to ELU and concerns how phonological information derived from the signal, matches/mismatches phonological representations in lexical and semantic long-term memory (LTM). When signals match, processing is rapid, automatic and implicit, and lexical activation proceeds smoothly. Given a mismatch, lexical activation fails, and working or short-term memory (WM/STM) is assumed to be invoked to engage in explicit repair strategies to disambiguate what was said in the conversation. In a recent study, negative long-term consequences of mismatch were found by means of relating hearing loss to episodic LTM in a sample of old hearing-aid wearers. STM was intact (Rönnberg et al.). Beneficial short-term consequences of a binary masking noise reduction scheme on STM was obtained in 4-talker babble for individuals with high WM capacity, but not in stationary noise backgrounds (Ng et al.). This suggests that individuals high on WM capacity inhibit semantic auditory distraction in 4-talker babble while exploiting the phonological benefits in terms of speech quality provided by binary masking (Wang). Both long-term and short-term mismatch effects, apparent in data sets including behavioral as well as subjective (Rudner et al.) data, need to be taken into account in the design of future hearing instruments.

Sudden sensorineural hearing loss (SSNHL) is commonly encountered in audiologic and otolaryngologic practice. SSNHL is most commonly defined as sensorineural hearing loss of 30 dB or greater over at least three contiguous audiometric frequencies occurring within a 72-hr period. Although the differential for SSNHL is vast, for the majority of patients an etiologic factor is not identified. Treatment for SSNHL of known etiology is directed toward that agent, with poor hearing outcomes characteristic for discoverable etiologies that cause inner ear hair cell loss. Steroid therapy is the current mainstay of treatment of idiopathic SSNHL in the United States. The prognosis for hearing recovery for idiopathic SSNHL is dependent on a number of factors including the severity of hearing loss, age, presence of vertigo, and shape of the audiogram.

The conditions of sound fields used in research, especially testing and fitting of hearing aids, are usually simplified or reduced to fundamental physical fields, such as the free or the diffuse sound field. The concepts of such ideal conditions are easily introduced in theoretical and experimental investigations and in models for directional microphones, for example. When it comes to real-world application of hearing aids, however, the field conditions are more complex with regard to specific stationary and transient properties in room transfer functions and the corresponding impulse responses and binaural parameters. Sound fields can be categorized in outdoor rural and urban and indoor environments. Furthermore, sound fields in closed spaces of various sizes and shapes and in situations of transport in vehicles, trains, and aircrafts are compared with regard to the binaural signals. In laboratory tests, sources of uncertainties are individual differences in binaural cues and too less controlled sound field conditions. Furthermore, laboratory sound fields do not cover the variety of complex sound environments. Spatial audio formats such as higher-order ambisonics are candidates for sound field references not only in room acoustics and audio engineering but also in audiology.