Medical tourism in emerging markets: The role of trust, networks, and word-of-mouth.

ABTRACT Despite the growing popularity of medical tourism (MT) in emerging markets (EMs), little is known about how healthcare providers operationalize. This article analyzes how healthcare providers meet different challenges to market MT in an EM setting. A qualitative method was used for data collection and conducting case studies on healthcare services in the Philippines. The results show that trust and network building are necessary for mitigating the unfavorable characteristics, instability and lack of legitimacy caused by institutional constraints in EM. Word-of-mouth is found to be important to attract new customers and disseminate information about MT services.

Biomass Assessment of Agricultural Crops Using Multi-temporal Dual-Polarimetric TerraSAR-X Data.

The biomass of three agricultural crops, winter wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), and canola (Brassica napus L.), was studied using multi-temporal dual-polarimetric TerraSAR-X data. The radar backscattering coefficient sigma nought of the two polarization channels HH and VV was extracted from the satellite images. Subsequently, combinations of HH and VV polarizations were calculated (e.g. HH/VV, HH + VV, HH × VV) to establish relationships between SAR data and the fresh and dry biomass of each crop type using multiple stepwise regression. Additionally, the semi-empirical water cloud model (WCM) was used to account for the effect of crop biomass on radar backscatter data. The potential of the Random Forest (RF) machine learning approach was also explored. The split sampling approach (i.e. 70% training and 30% testing) was carried out to validate the stepwise models, WCM and RF. The multiple stepwise regression method using dual-polarimetric data was capable to retrieve the biomass of the three crops, particularly for dry biomass, with R2 > 0.7, without any external input variable, such as information on the (actual) soil moisture. A comparison of the random forest technique with the WCM reveals that the RF technique remarkably outperformed the WCM in biomass estimation, especially for the fresh biomass. For example, the R 2 > 0.68 for the fresh biomass estimation of different crop types using RF whereas WCM show R 2 < 0.35 only. However, for the dry biomass, the results of both approaches resembled each other.

New perspectives on counselling in audiological habilitation/rehabilitation.

OBJECTIVE: To develop and apply a pedagogical method focusing on Empowerment, Empathy, Competence, and Counselling: the EC programme, and to present an initial evaluation. DESIGN: The EC programme was gradually developed within a study circle framework and in dialogue with study circle leaders and participants (clients) with hearing impairment (HI). An evaluation was carried out with the study circle leaders. STUDY SAMPLE: Seventeen upper secondary school students with HI took part in the development of the programme. Eighteen study circle leaders responded to a questionnaire. RESULTS: The EC programme developed consisted of films, CD, and DVD productions to increase insight into one's own hearing ability, to demonstrate for others what HI means, strategies to evaluate situations, and help to act constructively in social situations. The study circle leaders found most of the course material appropriate and easy to use, as a whole or in parts. The leaders' evaluations indicated that the clients had increased their knowledge about how the HI affected themselves and others. The clients had improved their self-confidence and their empathic view of others. CONCLUSION: The EC programme can be used in its entirety or in part. Participation may lead to increased empowerment, empathy, competence and counselling ability.

Hearing impairment and self-masking: listening during vocalization.

OBJECTIVES: To describe the masking effect of a vocalized [a:] on noise bands and speech in persons with mild-to-moderate hearing impairment (HI). DESIGN: The masked threshold of noise bands (250-8000 Hz), continuous discourse, and the amount of masking produced were determined. The maximal vocalization level was determined, that still allowed the subject to just follow the continuous discourse. STUDY SAMPLE: Twenty persons with sensory-neural HI, twelve with a high-frequency (HF) loss and eight with low-, mid-frequency or flat (LMF) loss. RESULTS: The [a:] gave a significantly higher masked threshold at 70 and 80 dBA vocalization for subjects with HF loss than for normal-hearing (NH) subjects, and somewhat higher thresholds than for those with LMF loss. The amount of masking produced was significantly smaller for subjects with HI than NH. CONCLUSIONS: It is important to consider masking effects of self-produced sounds in auditory rehabilitation, and in the future design of hearing aids.

Hearing speech in music.

The masking effect of a piano composition, played at different speeds and in different octaves, on speech-perception thresholds was investigated in 15 normal-hearing and 14 moderately-hearing-impaired subjects. Running speech (just follow conversation, JFC) testing and use of hearing aids increased the everyday validity of the findings. A comparison was made with standard audiometric noises [International Collegium of Rehabilitative Audiology (ICRA) noise and speech spectrum-filtered noise (SPN)]. All masking sounds, music or noise, were presented at the same equivalent sound level (50 dBA). The results showed a significant effect of piano performance speed and octave (P<.01). Low octave and fast tempo had the largest effect; and high octave and slow tempo, the smallest. Music had a lower masking effect than did ICRA noise with two or six speakers at normal vocal effort (P<.01) and SPN (P<.05). Subjects with hearing loss had higher masked thresholds than the normal-hearing subjects (P<.01), but there were smaller differences between masking conditions (P<.01). It is pointed out that music offers an interesting opportunity for studying masking under realistic conditions, where spectral and temporal features can be varied independently. The results have implications for composing music with vocal parts, designing acoustic environments and creating a balance between speech perception and privacy in social settings.

Assessment of auditory brainstem function in lead-exposed children using stapedius muscle reflexes.

The purpose of this study was to investigate the neurological integrity and physiological status of the auditory brainstem tracts and nuclei in children with chronic lead (Pb) exposure using non-invasive acoustic stapedius reflex (ASR) measurements of afferent and efferent-neuromuscular auditory function. Following audiological examinations, uncrossed (ipsilateral) and crossed (contralateral) brainstem ASR responses were evoked by pure tone (500, 1000, and 2000 Hz), and broadband noise (bandwidth: 125-4000 Hz) stimulus activators. The ASR threshold (ASRT), amplitude growth, and decay/fatigue were measured by conventional clinical middle ear immittance methods in a group of Andean children (age range: 2-18 years) with a history of chronic environmental Pb exposure from occupational Pb glazing. Blood lead (PbB) levels of the study group (n=117) ranged from 4.0 to 83.7 µg/dL with a mean PbB level of 33.5 µg/dL (SD: 23.6; median: 33.0: CDC III Classification). The PbB distribution data indicated that 77.8% (n=91) of the children had PbB levels greater than the CDC action line of 10 µg/dL. Repeatable, normal ASRTs were elicited for ipsilateral (mean: ≤90 dB HL) and contralateral (mean: ≤97 dB HL) stimulation for each acoustic activator. Spearman Rho correlation analysis indicated no significant association between PbB level and ipsilateral or contralateral ASRT for any of the stimulus activators. The ASR amplitude growth results showed typical growth functions with no Pb-associated aberrations. No statistical association was found between ASR decay/adaptation (ASRD) and PbB level for any of the stimulus activators. The results of stapedius muscle reflex testing using several stimulus activators showed no significant relationship between PbB level and the physiological integrity of the auditory brainstem mediated ASR responses in children with chronic Pb exposure and elevated PbB levels.

On the problem of listening while talking.

The Gauffin and Sundberg technique of assessing masking during vocalization was modified and tested on 22 normal-hearing and 20 hearing-impaired subjects. The masking effect of the vocalized [a:] on narrow-band noise pulses (250-8,000 Hz) and on test reading was studied. The results showed that the female voice was about 4 dB more efficient in masking external speech compared to the male voice and that the female voice had a high-frequency bias of masking the narrow-band noise, whereas the male voice had a low-frequency bias. Subjects with hearing impairment in the high frequencies were particularly impaired by the masking caused by their own voice. The implications for multilogue conversations and auditory rehabilitation are discussed.

Self-masking: Listening during vocalization. Normal hearing.

What underlying mechanisms are involved in the ability to talk and listen simultaneously and what role does self-masking play under conditions of hearing impairment? The purpose of the present series of studies is to describe a technique for assessment of masked thresholds during vocalization, to describe normative data for males and females, and to focus on hearing impairment. The masking effect of vocalized [a:] on narrow-band noise pulses (250-8000 Hz) was studied using the maximum vocalization method. An amplitude-modulated series of sound pulses, which sounded like a steam engine, was masked until the criterion of halving the perceived pulse rate was reached. For masking of continuous reading, a just-follow-conversation criterion was applied. Intra-session test-retest reproducibility and inter-session variability were calculated. The results showed that female voices were more efficient in masking high frequency noise bursts than male voices and more efficient in masking both a male and a female test reading. The male had to vocalize 4 dBA louder than the female to produce the same masking effect on the test reading. It is concluded that the method is relatively simple to apply and has small intra-session and fair inter-session variability. Interesting gender differences were observed.

Analysis of gene polymorphisms associated with K ion circulation in the inner ear of patients susceptible and resistant to noise-induced hearing loss.

Noise-induced hearing loss (NIHL) is one of the leading occupational health risks in industrialized countries. It results from an interaction between environmental and genetic factors, however the nature of the genetic factors contributing to NIHL has not yet been clarified. Here, we investigated whether genetic variations in 10 genes putatively involved in the potassium recycling pathway in the inner ear may influence susceptibility to noise. 99 SNPs were genotyped in Polish noise-exposed workers, categorized into susceptible and resistant subjects. The most interesting results were obtained for KCNE1 and KCNQ4 as we replicated associations that were previously reported in a Swedish sample set, hence confirming that they are NIHL susceptibility genes. Additionally we report significant associations in GJB1, GJB2, GJB4, KCNJ10 and KCNQ1, however due to the lack of replication in the Swedish sample set, these results should be seen as suggestive.

Vibrotactile identification of signal-processed sounds from environmental events.

This study compared three different signal-processing principles (eight basic algorithms)-transposing, modulating, and filtering-to find the principle(s)/algorithm(s) that resulted in the best tactile identification of environmental sounds. The subjects were 19 volunteers (9 female/10 male) who were between 18 and 50 years old and profoundly hearing impaired. We processed sounds produced by 45 representative environmental events with the different algorithms and presented them to subjects as tactile stimuli using a wide-band stationary vibrator. We compared eight algorithms based on the three principles (one unprocessed, as reference). The subjects identified the stimuli by choosing among 10 alternatives drawn from the 45 events. We found that algorithm and subject were significant factors affecting the results (repeated measures analysis of variance, p < 0.001). We also found large differences between individuals regarding which algorithm was best. The test-retest variability was small (mean +/- 95% confidence interval = 8 +/- 3 percentage units), and no correlation was noted between identification score and individual vibratory thresholds. One transposing algorithm and two modulating algorithms led to significantly better results than did the unprocessed signals (p < 0.05). Thus, the two principles of transposing and modulating were appropriate, whereas filtering was unsuccessful. In future work, the two transposing algorithms and the modulating algorithm will be used in tests with a portable vibrator for people with dual sensory impairment (hearing and vision).