Hands-free Equipment Research Articles

Use of mobile phone during pregnancy and the risk of spontaneous abortion.

BackgroundExposure to electromagnetic fields of cell phones increasingly occurs, but the potential influence on spontaneous abortion has not been thoroughly investigated.MethodsIn a case–control study, 292 women who had an unexplained spontaneous abortion at < 14 weeks gestation and 308 pregnant women > 14 weeks gestation were enrolled. Two data collection forms were completed; one was used to collect data about socioeconomic and obstetric characteristics, medical and reproductive history, and lifestyles. Another was used to collect data about the use of cell phones during pregnancy. For the consideration of cell phone effects, we measured the average calling time per day, the location of the cell phones when not in use, use of hands-free equipment, use of phones for other applications, the specific absorption rate (SAR) reported by the manufacturer and the average of the effective SAR (average duration of calling time per day × SAR). Analyses were carried out with statistical package state software(SPSS)v.16.ResultsAll the data pertaining to mobile phones were different between the two groups except the use of hands free devices (p < 0.001).ConclusionOur result suggests that use of mobile phones can be related to the early spontaneous abortions.

Acoustic user interfaces for ambient-assisted living technologies

This contribution discusses technologies for acoustic user interaction in ambient-assisted living (AAL) scenarios. Acoustic user interfaces allow for a natural and convenient way to interact with technical systems e.g. via sound or speech presentation or via speech input by means of automatic speech recognition (ASR) as well as by detection and classification of acoustic events. Older persons targeted by AAL technologies especially need more easy-to-use methods to interact with inherently complex supporting technology. As an example we designed and evaluated an application for acoustic user interaction with a multi-media reminder and calendar system. For this purpose, mainly older participants were involved in user studies to continuously evaluate and support the development strictly following a user-centred design process. The results suggest a wide acceptance of acoustic user interfaces by older users either for controlling inherently complex AAL systems by using robust ASR technologies or as a natural and ambient way of presenting information to the user. However, further research is needed to increase the robustness of ASR systems when using hands-free equipment, i.e. to provide a real ambient way of interaction, and to introduce personalised speech and sound presentation schemes accounting for the individual hearing capabilities and sound preferences.

Use of wireless telephones and self-reported health symptoms: a population-based study among Swedish adolescents aged 15-19 years.

BackgroundDespite the last years of rapid increase in use of wireless phones little data on the use of these devices has been systematically assessed among young persons. The aim of this descriptive cross-sectional study was to assess use of wireless phones and to study such use in relation to explanatory factors and self-reported health symptoms.MethodsA postal questionnaire comprising 8 pages of 27 questions with 75 items in total was sent to 2000 Swedish adolescents aged 15–19 years and selected from the population registry using a stratified sampling scheme.ResultsThe questionnaire was answered by 63.5% of the study subjects. Most participants reported access to a mobile phone (99.6%) and use increased with age; 55.6% of the 15-year-olds and 82.2% of the 19-year-olds were regular users. Girls generally reported more frequent use than boys. Use of wired hands-free equipment 'anytime' was reported by 17.4%. Cordless phones were used by 81.9%, and 67.3% were regular users. Watching TV increased the odds ratio for use of wireless phones, adjusted for age and gender. Some of the most frequently reported health complaints were tiredness, stress, headache, anxiety, concentration difficulties and sleep disturbances. Regular users of wireless phones had health symptoms more often and reported poorer perceived health than less frequent users.ConclusionAlmost all adolescence in this study used a wireless phone, girls more than boys. The most frequent use was seen among the older adolescents, and those who watched TV extensively. The study further showed that perceived health and certain health symptoms seemed to be related to the use of wireless phones. However, this part of the investigation was explorative and should therefore be interpreted with caution since bias and chance findings due to multiple testing might have influenced the results. Potentially this study will stimulate more sophisticated studies that may also investigate directions of associations and whether, or to what degree, any mediation factors are involved.

Ownership and use of wireless telephones: a population-based study of Swedish children aged 7–14 years

BackgroundRecent years have seen a rapid increase in the use of mobile phones and other sources of microwave radiation, raising concerns about possible adverse health effects. As children have longer expected lifetime exposures to microwaves from these devices than adults, who started to use them later in life, they are a group of special interest.MethodsWe performed a population-based study to assess ownership and use of mobile phones and cordless phones among children aged 7–14 years. A questionnaire comprising 24 questions was sent to 2000 persons selected from the Swedish population registry using a stratified sampling scheme.ResultsThe response rate was 71.2%. Overall, 79.1% of the respondents reported mobile phone access, and 26.7% of them talked for 2 minutes or more per day. Of those who reported mobile phone access, only 5.9% reported use of hands-free equipment. Use of cordless phones was reported by 83.8% of the respondents and 38.5% of them talked for 5 minutes or more per day. Girls generally reported more frequent use than boys.ConclusionThis study showed that most children had access to and used mobile and cordless phones early in life and that there was a rapid increase in use with age. It also showed very low use of hands-free equipment among children with mobile phone access, and finally that girls talked significantly more minutes per day using mobile and cordless phones than boys did.

Development and evaluation of a prototype communication navigator for the driving environment

The progress in mobile multimedia devices has made it easier to conduct mobile multimedia communication while driving. The authors have conceived a communication navigator for the driving environment, which is designed to ensure safe driving during multimedia communication. The communication navigator is intended to provide safety without sacrificing comfort in communication, by controlling multimedia communication on the basis of the state of the driving environment. To design the navigator, it was necessary to identify a control parameter and select the optimal threshold for it. We found that steering operation could be an important indicator of hazardous driving situations. We developed a prototype system to confirm empirically the validity of the selected indicator and its threshold. The results obtained from the prototype system were compared with the data collected in real driving on the road. We then equipped the prototype with a communication navigator for the driving environment, which controls multimedia communication based on movements of the steering wheel. Experiments were conducted with test subjects to verify that steering operation was a useful parameter for control. The experimental results showed that the communication navigator is three times as effective as hands-free equipment in reducing the collision probability. © 2000 Scripta Technica, Electron Comm Jpn Pt 1, 84(1): 12–20, 2001

A system for speech enhancement in the context of hands-free radiotelephony with combined noise reduction and acoustic echo cancellation

This paper addresses typical problems encountered with hands-free equipment in the context of GSM radiotelephony. We first summarise some important characteristics of the noise field in moving vehicles, and we also describe the acoustical echo phenomenon. We show that, in order to provide sufficiently high speech quality, these hands-free equipments should include noise reduction (NR) and acoustic echo control (AEC) devices. We then describe two possible structures combining noise reduction and acoustic echo control. As a conclusion, we raise the fact that the choice of a particular structure, among those proposed, is conditioned by the performance of the adaptation algorithm of the AEC solution.