89 research outputs found
Auditory excitation patterns : the significance of the pulsation threshold method for the measurement of auditory nonlinearity
The auditory system is the toto[ of organs that translates an acoustical signal into
the perception of a sound. An acoustic signal is a vibration. It is decribed by physical
parameters. The perception of sound is the awareness of a signal being present
and the attribution of certain qualities to this awareness. These qualities are called
percepts. Examples of percepts are pitchr loudness and timbre.
The percepts reflect the way in which the auditory system analyses and processes
acoustic signals. Hence they also determine the most useful ways of describing the
signals in physical terms.
Frequency analysis is one of the most important processes involved in hearing. It is
described in mathematical form by Fourier theory. This theory states that every repetitive
signal can be described uniquely as a sum of sine waves. These sine waves
are called frequency components. The elementary signal, therefore, consists of only
one frequency component and is a sine-wave signal. The sine wave thus is also the
elementary signal for our ear; we call the perception of this signal a pure tone.
Signals consisting of more than one component are perceived as complex sounds
Adolescents and MP3 Players: Too Many Risks, Too Few Precautions
OBJECTIVE. The goal was to assess risky and protective listening behaviors of adolescent
users of MP3 players and the association of these behaviors with demographic
characteristics and frequency of use.
METHODS. In 2007, 1687 adolescents (12–19 years of age) in 68 classes in 15 Dutch
secondary schools were invited to complete questionnaires about their music-listening
behaviors.
RESULTS. Ninety percent of participants reported listening to music through earphones
on MP3 players; 32.8% were frequent users, 48.0% used high volume settings, and
only 6.8% always or nearly always used a noise-limiter. Frequent users were _4
times more likely to listen to high-volume music than were infrequent users, and
adolescents in practical prevocational schools were more than twice as likely to listen
to high-volume music as were those attending preuniversity education.
CONCLUSIONS. When using MP3 players, adolescents are very likely to engage in risky
listening behaviors and are unlikely to seek protection. Frequent MP3 player use is
an indicator of other risky listening behaviors, such as listening at high volumes and
failing to use noise-limiter
Comparison of speech intelligibility in quiet and in noise after hearing aid fitting according to a purely prescriptive and a comparative fitting procedure
We compared two different types of hearing-aid fitting procedures in a double-blind randomized clinical study. Hearing aid fittings based on a purely prescriptive procedure (the NAL-RP formula) were compared to a comparative fitting procedure based on optimizing speech intelligibility scores. Main outcome measures were improvement of speech intelligibility scores in quiet and in noise. Data were related to the real-ear insertion responses that were measured after fitting. For analysis purposes subgroups were composed according to degree of hearing loss, characterized by unaided speech intelligibility in quiet, previous experience with hearing aids, unilateral or bilateral fittings and type of hearing aid. We found equal improvement of speech intelligibility in quiet, while fitting according to the prescriptive formula resulted in a somewhat better performance as expressed by the speech-to-noise ratio in comparison to the comparative procedure. Both procedures resulted in comparable real-ear insertion responses
The design of a project to assess bilateral versus unilateral hearing aid fitting
Binaural hearing provides advantages over monaural in several ways, particularly in difficult listening situations. For a person with bilateral hearing loss, the bilateral fitting of hearing aids thus seems like a natural choice. However, surprisingly few studies have been reported in which the additional benefit of bilateral versus unilateral hearing aid use has been investigated based on real-life experiences. Therefore, a project has been designed to address this issue and to find tools to identify people for whom the drawbacks would outweigh the advantages of bilateral fitting. A project following this design is likely to provide reliable evidence concerning differences in benefit between unilateral and bilateral fitting of hearing aids by evaluating correlations between entrance data and outcome measures and final preferences
Potential barriers and facilitators for implementation of an integrated care pathway for hearing-impaired persons: an exploratory survey among patients and professionals
BACKGROUND: Because of the increasing costs and anticipated shortage of Ear Nose and Throat (ENT) specialists in the care for hearing-impaired persons, an integrated care pathway that includes direct hearing aid provision was developed. While this direct pathway is still under investigation, in a survey we examined expectations and potential barriers and facilitators towards this direct pathway, of patients and professionals involved in the pathway. METHODS: Two study populations were assessed: members of the health professions involved in the care pathway for hearing-impaired persons (general practitioners (GPs), hearing aid dispensers, ENT-specialists and clinical audiologists) and persons with hearing complaints. We developed a comprehensive semi-structured questionnaire for the professionals, regarding expectations, barriers, facilitators and conditions for implementation. We developed two questionnaires for persons with hearing complaints, both regarding evaluations and preferences, and administered them after they had experienced two key elements of the direct pathway: the triage and the hearing aid fitting. RESULTS: On average GPs and hearing aid dispensers had positive expectations towards the direct pathway, while ENT-specialists and clinical audiologists had negative expectations. Professionals stated both barriers and facilitators towards the direct pathway. Most professionals either supported implementation of the direct pathway, provided that a number of conditions were satisfied, or did not support implementation, unless roughly the same conditions were satisfied. Professionals generally agreed on which conditions need to be satisfied. Persons with hearing complaints evaluated the present referral pathway and the new direct pathway equally. Many, especially older, participants stated however that they would still visit the GP and ENT-specialist, even when this would not be necessary for reimbursement of the hearing aid, and found it important that the ENT-specialist or Audiological Centre evaluated their hearing aid. CONCLUSION: This study identified professional concerns about the direct pathway for hearing-impaired persons. Gaps exist in expectations amongst professions. Also gaps exist between users of the pathway, especially between age groups and regions. Professionals are united in the conditions that need to be fulfilled for a successful implementation of the direct pathway. Implementation on a regional level is recommended to best satisfy these conditions
Hearing in adults with Pompe disease
Hearing loss has been recognized as an important cause of morbidity in infants with Pompe disease, a metabolic disorder caused by deficiency of acid α-glucosidase. It is unknown whether hearing is also affected in adult Pompe patients. We have studied the prevalence, severity, and type of hearing loss in 58 adult patients using tympanometry and pure-tone audiometry. Compared to normative data (International Organisation for Standardisation standard 7029), 72% of patients had impaired hearing thresholds at one or more frequencies in at least one ear. All measured frequencies were equally affected. All patients had a sensorineural type of hearing loss, pointing to cochlear or retrocochlear pathology. Categorised according to the standards of the World Health Organisation 21% of patients had a clinically relevant hearing loss (16% slight, 3% moderate, 2% profound). Though this suggests that hearing loss occurs in a considerable number of patients with Pompe disease, this prevalence is similar to that in the general population. Therefore, we conclude that hearing loss is not a specific feature of Pompe disease in adults
Choosing between measures: comparison of EQ-5D, HUI2 and HUI3 in persons with hearing complaints
OBJECTIVES: To generate insight into the differences between utility measures EuroQol 5D (EQ-5D), Health Utilities Index Mark II (HUI2) and Mark III (HUI3) and their impact on the incremental cost-effectiveness ratio (ICER) for hearing aid fitting METHODS: Persons with hearing complaints completed EQ-5D, HUI2 and HUI3 at baseline and, when applicable, after hearing aid fitting. Practicality, construct validity, agreement, responsiveness and impact on the ICER were examined. RESULTS: All measures had high completion rates. HUI3 was capable of discriminating between clinically distinctive groups. Utility scores (n = 315) for EQ-5D UK and Dutch tariff (0.83; 0.86), HUI2 (0.77) and HUI3 (0.61) were significantly different, agreement was low to moderate. Change after hearing aid fitting (n = 70) for HUI2 (0.07) and HUI3 (0.12) was statistically significant, unlike the EQ-5D UK (0.01) and Dutch (0.00) tariff. ICERs varied from 647,209 euros/QALY for the EQ-5D Dutch tariff to 15,811 euros/QALY for HUI3. CONCLUSION: Utility scores, utility gain and ICERs heavily depend on the measure that is used to elicit them. This study indicates HUI3 as the instrument of first choice when measuring utility in a population with hearing complaints, but emphasizes the importance of a clear notion of what constitutes utility with regard to economic analyse
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