Cordless Phones Research Articles

Link between Wi-Fi, cordless devices, mobile phone usage patterns, and behavioral problems among Japanese children: A prospective cohort study

BackgroundWith the recent advent of technology, it is important to confirm the health and safety of the youth. This study aimed to prospectively evaluate the relationship between Wi-Fi, cordless phones, and mobile phone usage patterns and behavioral problems. MethodsThis study involved 2465 children aged 8–17 years from the Hokkaido Study on Environment and Children’s Health from October 2020 to January 2021, with a follow-up from September 2021 to March 2022. The mother–child dyad provided information on the presence of residential Wi-Fi and cordless phones, cordless phone call duration, and mobile phone usage pattern (duration of calls using mobile network and internet, online audio streaming, online video streaming, and playing online games) via a baseline questionnaire. Based on the scores on Strength and Difficulties Questionnaire at baseline and follow-up, the children were categorized into four groups: normal, persistent, improved, and concurrent. ResultsNo significant association was found between Wi-Fi, mobile phone calls via mobile networks, and behavioral problems. Cordless phone at home had higher odds for improvement in total difficulty scores, and cordless phone for calling more than 4 min per week had lower odds of persistent problematic prosocial behavior. Longer duration of mobile phone calling via the internet (>40 min/week) had higher odds of concurrent total difficulties. Mobile phone calling via mobile network for <5 min per week had higher odds for improved total difficulty scores. Audio streaming via mobile phones for 60–120 min had lower odds of persistent total difficulties. ConclusionOur results showed sporadic findings between residential RF-EMF indoor sources and mobile phone usage pattern. These observed findings could be affected by residual confounding and chance findings. Ongoing follow-up studies are necessary to further explore this association through detailed exposure assessment and addressing the potential limitations of our study.

The association between real-life markers of phone use and cognitive performance, health-related quality of life and sleep

IntroductionThe real-life short-term implications of electromagnetic fields (RF-EMF) on cognitive performance and health-related quality of life have not been well studied. The SPUTNIC study (Study Panel on Upcoming Technologies to study Non-Ionizing radiation and Cognition) aimed to investigate possible correlations between mobile phone radiation and human health, including cognition, health-related quality of life and sleep. MethodsAdult participants tracked various daily markers of RF-EMF exposures (cordless calls, mobile calls, and mobile screen time 4 h prior to each assessment) as well as three health outcomes over ten study days: 1) cognitive performance, 2) health-related quality of life (HRQoL), and 3) sleep duration and quality. Cognitive performance was measured through six “game-like” tests, assessing verbal and visuo-spatial performance repeatedly. HRQoL was assessed as fatigue, mood and stress on a Likert-scale (1–10). Sleep duration and efficiency was measured using activity trackers. We fitted mixed models with random intercepts per participant on cognitive, HRQoL and sleep scores. Possible time-varying confounders were assessed at daily intervals by questionnaire and used for model adjustment. ResultsA total of 121 participants ultimately took part in the SPUTNIC study, including 63 from Besancon and 58 from Basel. Self-reported wireless phone use and screen time were sporadically associated with visuo-spatial and verbal cognitive performance, compatible with chance findings. We found a small but robust significant increase in stress 0.03 (0.00–0.06; on a 1–10 Likert-scale) in relation to a 10-min increase in mobile phone screen time. Sleep duration and quality were not associated with either cordless or mobile phone calls, or with screen time. DiscussionThe study did not find associations between short-term RF-EMF markers and cognitive performance, HRQoL, or sleep duration and quality. The most consistent finding was increased stress in relation to more screen time, but no association with cordless or mobile phone call time.

A miniaturized antenna for Mobile Broad-Band/Cordless Phones/Wireless Audio Devices/ISM

This research introduces the design and simulation of a monopole antenna with a simple ground plane, specifically developed for dual-band communication. The antenna consists of a radiating patch, feed line, and ground plane, and it was fabricated on an FR-4 substrate. The operating frequency bands of the antenna cover 2.5–2.7 GHz and 3.9–4.6 GHz. By carefully selecting the dimensions, the antenna achieves resonance frequencies at 2.6 GHz and 4.2 GHz, with corresponding bandwidths of 200 MHz and 700 MHz. The research provided excellent impedance matching for the antenna, as indicated by the measured return loss (S11) values of -29.35 dB and -22.48 dB, surpassing the required criterion of S11 &amp;lt; -10 dB. The compact size of the antenna, measuring 12×24×1.6 mm³, makes it highly suitable for applications with space limitations. The antenna performance was extensively analyzed through simulations utilizing High-Frequency Structure Simulator (HFSS) software. The results validate its effectiveness for two specific frequency bands:2.6 GHz for mobile broadband service and 4.2 GHz for various applications such as cordless phones, wireless audio devices, and industrial, Scientific, and Medical Networks (ISM). This research lays a solid foundation for future developments in dual-band communication antennas, offering potential benefits in terms of connectivity and communication efficiency.

Ivo van Hove and Almodóvar: Remixing The Human Voice

Ivo van Hove and Almodóvar: Remixing <i>The Human Voice</i>

Systematic review of the physiological and health-related effects of radiofrequency electromagnetic field exposure from wireless communication devices on children and adolescents in experimental and epidemiological human studies.

BackgroundFor more than 20 years, the potential health risks of radiofrequency electromagnetic field (RF EMF) exposure from mobile communication devices on children and adolescents have been examined because they are considered sensitive population groups; however, it remains unclear whether such exposure poses any particular risk to them.ObjectivesThe aim of this review was to systematically analyze and evaluate the physiological and health-related effects of RF EMF exposures from wireless communication devices (mobile phones, cordless phones, Bluetooth, etc.) on children and adolescents.MethodsThis review was prepared according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Methodological limitations in individual studies were assessed using the Office of Health Assessment and Translation (OHAT) Risk-of-Bias Rating Tool for Human and Animal Studies.ResultsA total of 42 epidemiological and 11 experimental studies were eligible for this review. Most of the studies displayed several methodological weaknesses that limited the internal validity of the results. Due to a lack of consistency regarding the outcomes as well as the lack of scientific rigor in most reviewed studies, the body of evidence for the effects of RF EMF of mobile communication devices on subjective symptoms, cognition, and behavior in children and adolescents was low to inadequate. Evidence from the studies investigating early childhood development, brain activity, cancer, and physiological parameters was considered inadequate for drawing conclusions about possible effects.DiscussionOverall, the body of evidence allows no final conclusion on the question whether exposure to RF EMF from mobile communication devices poses a particular risk to children and adolescents. There has been rapid development in technologies generating RF EMF, which are extensively used by children and adolescents. Therefore, we strongly recommend high-quality systematic research on children and adolescents, since they are generally considered as sensitive age groups.

Optimization of Parallel Coupled Filter Using Genetic Algorithm for C Band Applications

PCML filter with five coupled lines is designed using mathematical calculations then the same PCML filter is optimized using GA for reduction in size and bandwidth enhancement. Optimized filter is compact and total size reduction is 37.66% after optimization and bandwidth enhancement after optimization is 84.3%. Both filters are useful for C band applications, wireless communication, satellite communication, cordless phones, surveillance, and weather monitoring using weather radar. The substrate used is FR4 epoxy with a dielectric constant 4.4 and thickness 1.6 mm.

Investigation of the Effects of Pollution Caused by the Emission of Electromagnetic Waves on Human Health

Electromagnetic force, despite its useful efficiency and achievements, if not controlled and managed, is very dangerous for humans and will have irreversible effects that will remain even after thousands of years. Telecommunication devices such as mobile phones, cordless phones, VHF and SSB wireless and radar .... emit electromagnetic waves that when these waves collide with the living tissue of the body, cause changes in them that They endanger life.&#x0D; Magnetic and electric fields are generated by power lines, electrical wires, and electrical equipment, and are the invisible power lines that exist around each device, and its power increases with increasing voltage. The electromagnetic field is generated by electrical appliances such as personal computers, televisions, refrigerators, etc., as well as high-voltage power lines. The electromagnetic field disrupts the nervous system and the growth and development and repair of cells, leading to unknown diseases such as cancers, brain tumors and infertility in humans. Therefore, people who are exposed to such fields frequently and for a long time, as well as people working in the electrical and telephone industries, TV repairmen and welders are more vulnerable. Therefore, we must create a suitable environment for work and activity by installing carcinogen control devices in the workplace and identifying the sources of electromagnetic radiation production, observing safety points in the workplace and, if possible, using equipment that has the least amount of electromagnetic waves.

Dual Band Partial Ground Symmetrical Slit Rectangular Monopole Microstrip Antenna for Wireless Communication Applications

The dual band partial ground symmertrical slit monopole rectangular microstrip antenna for broadband wireless communication applications is proposed in this paper. In the proposed geometry symmetrical slits are introduced at rectangular microstrip patch close to radiating edges. The height Lg on ground plane introduced the gap which hepls to resonate the designed antenna near to designed frequency with increased bandwith. The symmetrical slits on edges of radiating patch provides the dual operationbands. The impedance bandwidth covers the frequency range from 1.36 - 2.3 GHz and 3 - 5 GHz with respective magnitude of BW1=56.28%, BW2=46.41%. Maximum gain achieved is 4dB. The antenna exhibits the nearly omnidirectional radiation patterns at resonating frequencies. The proposed antenna can be used for cellular LTE band frequency (1.700 -2.100 GHz), ISM (2.4 - 2.4835 GHz) for Microwave ovens, cordless phones, medical diathermy machines, military radars and industrial heaters, Wi-Fi, Bluetooth, GPS ( 1.2-1.6 GHz), PCS (1.8 GHz to 2 GHz) applications.

Wireless phone use in childhood and adolescence and neuroepithelial brain tumours: Results from the international MOBI-Kids study.

In recent decades, the possibility that use of mobile communicating devices, particularly wireless (mobile and cordless) phones, may increase brain tumour risk, has been a concern, particularly given the considerable increase in their use by young people. MOBI-Kids, a 14-country (Australia, Austria, Canada, France, Germany, Greece, India, Israel, Italy, Japan, Korea, the Netherlands, New Zealand, Spain) case-control study, was conducted to evaluate whether wireless phone use (and particularly resulting exposure to radiofrequency (RF) and extremely low frequency (ELF) electromagnetic fields (EMF)) increases risk of brain tumours in young people. Between 2010 and 2015, the study recruited 899 people with brain tumours aged 10 to 24years old and 1,910 controls (operated for appendicitis) matched to the cases on date of diagnosis, study region and age. Participation rates were 72% for cases and 54% for controls. The mean ages of cases and controls were 16.5 and 16.6years, respectively; 57% were males. The vast majority of study participants were wireless phones users, even in the youngest age group, and the study included substantial numbers of long-term (over 10years) users: 22% overall, 51% in the 20-24-year-olds. Most tumours were of the neuroepithelial type (NBT; n=671), mainly glioma. The odds ratios (OR) of NBT appeared to decrease with increasing time since start of use of wireless phones, cumulative number of calls and cumulative call time, particularly in the 15-19years old age group. A decreasing trend in ORs was also observed with increasing estimated cumulative RF specific energy and ELF induced current density at the location of the tumour. Further analyses suggest that the large number of ORs below 1 in this study is unlikely to represent an unknown causal preventive effect of mobile phone exposure: they can be at least partially explained by differential recall by proxies and prodromal symptoms affecting phone use before diagnosis of the cases. We cannot rule out, however, residual confounding from sources we did not measure. Overall, our study provides no evidence of a causal association between wireless phone use and brain tumours in young people. However, the sources of bias summarised above prevent us from ruling out a small increased risk.

A Pre-Experimental Study to Assess the Effectiveness of Video Assisted Teaching Programme on Knowledge Regarding Health Hazards of Using Mobile Phone Among School Going Children of Selected Schools of District Kangra, Himachal Pradesh

Background: School going children represents a period of transition between childhood and adulthood. In recent years, adoption of mobile phones by school going children has been a global phenomenon. Several studies revealed that during use mobile phone and cordless phone emit radiofrequency (RF) radiation that can possibly cause cancer and long-term health issues. Therefore, children need awareness regarding health hazards of using mobile phone.Material and methods: A quantitative research approach and pre-experimental research design was adopted to conduct study. The non-probability purposive sampling technique were used to select 60 school going children of District Kangra, Himachal Pradesh. A Self-structured knowledge questionnaire was used to assess knowledge score. Analysis of collected data was done according to the objectives of the study and data analyzed by using descriptive and inferential statistics.Results: The mean pre-test knowledge score was 14.53 where 70% school going children were having moderately adequate knowledge, 25% were having inadequate knowledge and only 5% were having adequate knowledge. Whereas the mean post-test knowledge score was 20.77 where 55% were having adequate knowledge, 43.33% were having moderately adequate knowledge and only 1.67% having inadequate knowledge. Hence, results revealed that the post-test knowledge score (20.77) was significantly higher than pre-test (14.53) and obtained ‘t’ value has been found statistically very highly significant (8.458) at p&lt;0.001 level of significance.Interpretation and conclusion: The study concluded that the video assisted teaching program was effective in improving the knowledge regarding health hazards of using mobile phone among school going children. As school going children were easily attracted toward video assisted teaching programme and show interest also.

Repurposing acoustic modulation schemes to support ultrasonic IoT NFC

Traditional radio based communication scenarios for both Wireless Personal Area Network (WPAN) and Low Power Wide Area Network (LPWAN) schemes rely heavily on modulation mechanisms over Industrial, Scientific and Medical (ISM) bands. These bands are increasingly getting overcrowded with cordless phone, BLE, Wi‐Fi, IEEE 802.15.4, LoRa and other transmissions. On the other hand, ultrasonic communications can be a valid alternative to some of these radio technologies by providing Near Field Communication (NFC) in the context of WPANs. In this paper we present physical and link layers that rely on a well‐known and proven acoustic modulation mechanism that is adapted and extended to handle the requirements of Internet of Things (IoT) networks over the ultrasonic spectrum. Specifically, the proposed mechanism attempts to comply with one of the most important requirements of IoT, that is, the support of end‐to‐end IPv6 connectivity. This support is critical to enable the integration with IoT devices and applications.

Original Findings Confirmed in Replication Study: Provocation with 2.4 GHz Cordless Phone affects the Autonomic Nervous System (ANS) as measured by Heart Rate Variability (HRV)

This is a double-blind, placebo-controlled replication of a study that we previously conducted in Colorado with 25 subjects designed to test the effect of radio frequency radiation (RFR) generated by the base station of a cordless phone on heart rate variability (HRV). In this study, we analyzed the response of 69 subjects between the ages of 26 and 80 in both Canada and the USA. Subjects were exposed to radiation for 3-min intervals generated by a 2.4-GHz cordless phone base station (3–8 microW/cm2). Prior to provocation we conducted an orthostatic test to assess the state of adrenal exhaustion, which interferes with a person’s ability to mount a response to a stressor. A few participants had a severe reaction to the RFR with an increase in heart rate and altered HRV indicative of an alarm response to stress. Based on the HRV analyses of the 69 subjects, 7% were classified as being “moderately to very sensitive”, 29% were “little to moderately sensitive”, 30% were “not to a little sensitive” and 6% were “unknown”. These results are not psychosomatic and are not due to electromagnetic interference. Twenty-five percent of the subjects’ self-proclaimed sensitivity corresponded to that based on the HRV analysis, while 32% overestimated their sensitivity and 42% did not know whether or not they were electrically sensitive. Of the 39 participants who claimed to experience some electrical hypersensitivity, 36% claimed they also reacted to a cordless phone and experienced heart symptoms and, of these, 64% were classified as having some degree of electrohypersensitivity (EHS) based on their HRV response. Novel findings include documentation of a delayed response to radiation. This protocol underestimates the reaction to electromagnetic radiation and may provide a false negative for those with a delayed reaction and/or with adrenal exhaustion. Orthostatic HRV testing combined with provocation testing may provide a useful diagnostic tool for some sufferers of EHS when they are exposed to electromagnetic radiation. It can be used to confirm EHS but not to reject EHS as a diagnosis since not everyone with EHS has an ANS reaction to electromagnetic radiation.

Wireless Communication Through Networks and Its Applications

Communication started with Telegraphy in the 1840s developing with Telephony some decade later and radio at the beginning of the century. The modern Telecommunication age is here. We live in a world of cordless phones, cells, Mobiles, Satellite TV. This is the information age. New Weather sports are made available to us almost instantly via Modern digital networks. Telephones, radio, television have become integral parts of modernizing society. My motto is to present cellular and mobile communication. Cellular communication listed some 200 million subscribers with an average of 1,50,000 new ones joining each day. The demand for basic voice and data services has stretched the limits of wireless communication in meeting the needs of an increasingly mobile market. The market is stretching the technology calling for the addition of videoconferencing image capability and data transfer through high-speed networks. The contents is explained in the preceding papers are ‘The Cellular Concept’, which includes Introduction to mobile telephony and the basic elements of the Cellular concept with the frequency allocations. The future content explains the operation of the Cellular system and the Cellular principle. The future scope of mobile and Cellular communication has also been explained.

Design and Analysis of Circular Monopole antenna for WLAN and WI-Max Application in S band

In today’s existence, the technology for communication is continuously growing. The agile achievement in ultra-broadband antennas in wireless communication is increased. A circular monopole microstrip patch antenna has been developed in this research paper. The parameters grandiose by antenna perfmonance are researched. The design is designed to achieve desired gain and bandwidth at 2.4 GHz frequency, with a defected ground system (DGS). This antenna design has been effectuated using FR-4 as the dielectric substrate with 4.3 as dielectric constant. In computer simulation technology (CST) the model monopole circular microstrip patch antenna is simulated and the results needed are achieved. The S11 parameter is obtained as -17.28 decibels which is below -10 decibel. The gain obtained at 2.4 GHz frequency is 1.730 decibel. Application in S band devices, including Wi-Max, WLAN, radio altimeter, cordless phones, wireless headphones etc., were built in this research article.

Electromagnetic Field EMF ) R adiation and its I mpact on Our Health and Eco System

Electromagnetic Field (EMF) radiation is a wave of the electromagnetic field. The radiation from mobile phones, cordless phones, mobile antennas, and many other devices pose health threats, especially when they are close to the body for extended period. In humans and animals, bioelectrical signals regulate many processes. Therefore, EMF radiations can interfere with the natural way of how our body works; it affects our body at cell level. Moreover, the impact of EMF radiation on our eco-system is serious due to growing number of broadcasting antennas, mobile communications base stations etc. World Health Organization (WHO) says the EMF radiations produced by mobile phone is classified by the International Agency for Research on Cancer (IARC) as possible carcinogen to humans. The aim of this research paper is to survey on mobile phone usage and EMF radiation awareness. Our results from analyzing the survey data shows that 86.2% people keep their mobile phones near their ears while receiving calls, 77.7% people keep mobile phones in their bedroom before going to bed. Based on the results and considering the major impact of EMF radiations, we propose innovative house design called Radiation Reduced Dwelling (RRD) by which the EMF radiation exposure can be minimized at home. Moreover, we propose an Environment Friendly Link (EFL) by which mobile base stations case be avoided in forests and hilly areas.

Comments on "Diverse Radiofrequency Sensitivity and Radiofrequency Effects of Mobile or Cordless Phone near Fields Exposure in Drosophila Melanogaster"

Geronikolou, et al. followed the same experimental methodology without reporting replication or even citing the original study. Then, they differentiated on secondary points - employing a different statistical method, calculating theoretically the near-field instead of measuring it, not sham-exposing the control groups, and including experiments with cordless phones based on the same procedures - which led them to serious flaws and misleading conclusions. Our present commentary is a necessary action to protect authorship and restore science in regards to experiments with mobile and cordless phones.

Radiofrequency electromagnetic fields exposure, screen time, brain morphology, and attention problems in school-age children

PDS 73: Neurological effects, Johan Friso Foyer, Floor 1, August 26, 2019, 10:30 AM - 12:00 PM Purpose: To investigate the association between radiofrequency electromagnetic fields (RF-EMF) exposure, screen time, and brain morphology in school-age children and to assess whether brain morphology mediates an association between RF-EMF exposure with screen time and behaviour problems. Methods: Cross-sectional study in children aged 9-12 years from the Generation R Study, a population-based birth cohort in Rotterdam, The Netherlands (n=2,592). Information on mobile and cordless phone calls, mobile phone uses other than calling, use of tablet and laptop, console/computer gaming, and television was reported by the parents. Residential RF-EMF exposure from mobile phone base stations was estimated using a 3D geospatial radio wave propagation model. An integrated model to estimate RF-EMF dose (J/kg/day) to the brain was calculated using all collected information. Information on brain volumes and cortical thickness was extracted from magnetic resonance imaging scans. Parental-reported behaviour problems were assessed using the Child Behavior Checklist. Results: RF-EMF dose to the brain was not related to brain morphology alterations. However, other mobile phone uses was associated with a smaller parietal cortex [β -33.4 (95%CI -55.2;-11.6) per each increase in 1 minute]. Higher television use was associated with smaller total brain volume [β -105.0 mm3 (95%CI -159.7;-50.2) per each increase in 1 minute], and with higher attention problems [β 0.0018 (95%CI 0.0001; 0.0036) and ADHD symptoms [0.0023 (95% CI 0.0007; 0.0039) per each increase in 1 minute]. The observed smaller total brain volume partially mediated the association between television use and attention problems. None of the exposure variables was associated with cortical thickness. Conclusion: RF-EMF dose to the brain was not associated with brain morphology alterations. Longer use of screen devices, in particular television use, was associated with smaller brain volume, and smaller brain volume partially mediated the association between higher television use and higher attention problems.

Building science and radiofrequency radiation: What makes smart and healthy buildings

Radiofrequency radiation (RFR), used for wireless communications and “smart” building technologies, including the “Internet of Things,” is increasing rapidly. As both RFR exposures and scientific evidence of harmful effects increase apace, it is timely to heed calls to include low RFR levels as a performance indicator for the health, safety and well-being of occupants and the environment.Adverse biochemical and biological effects at commonly experienced RFR levels indicate that exposure guidelines for the U.S., Canada and other countries are inadequate to protect public health and the environment.Some industry liability insurance providers do not offer coverage against adverse health effects from radiation emitted by wireless technologies, and insurance authorities deem potential liability as “high.” Internationally, governments have enacted laws, and medical and public health authorities have issued recommendations, to reduce and limit exposure to RFR.There is an urgent need to implement strategies for no- or low-RFR emitting technologies, and shielding, in building design and retrofitting. These strategies include installing wired (not wireless) Internet networks, corded rather than cordless phones, and cable or wired connections in building systems (e.g., mechanical, lighting, security). Building science can profit from decades of work to institute performance parameters, operationalizing prudent guidelines and best practices. The goal is to achieve RFR exposures that are ALARA, “As Low As Reasonably Achievable.”We also challenge the business case of wireless systems, because wired or cabled connections are faster, more reliable and secure, emit substantially less RFR, and consume less energy in a sector with rapidly escalating greenhouse gas emissions.

The Hazards of Building in the Vicinity of Electromagnetic Fields: Lessons for Building Code Enforcement in Nigeria

This paper dealt with the topic of electromagnetic field (EMF) and its effects on building occupants when such buildings are located within the vicinity of the field. Two main sources of EMF, namely, high voltage power transmission lines and cellular towers, were reviewed. Empirical evidence revealed that they have a tendency to emit electromagnetic fields and they have been determined to be hazardous to building occupants. Studies have also established that when buildings are erected within an unsafe distance to the fields, occupants of such buildings become exposed to health risks. Indeed, evidence exists to show that exposure to these fields can lead to cancer in children and that men exposed to the fields are also susceptible to health risks. Studies by the International Agency for Research on Cancer (IARC) among others, assessed the carcinogenicity of radiofrequency electromagnetic fields (RF-EMF) positing that human responses to RF-EMF can occur from use of personal devices such as mobile telephones, cordless phones, Bluetooth, and amateur radios; from occupational sources such as high frequency dielectric and induction heaters, and high-powered pulsed radars. Exposures can also occur from environmental sources such as mobile phone base stations, broadcast antennas, and medical applications. This paper also examined standards for safe distances and buffers for building location with respect to EMFs and made recommendations for policy makers and building code enforcement services. Keywords : Building Codes, Epidemiology, Carcinogenicity, Radio Frequency, Extreme Low Frequency, Non-Ionizing Radiation DOI : 10.7176/JETP/9-3-01 Publication date :March 31 st 2019

Effect of Various Electronic Devices on the Performance of Electronic Apex Locator.

Apex locators are important devices that can be used to determine working length during root canal treatment. However, it is not known whether electronic devices with various wave length frequencies influence the accuracy of apex locators. The aim of this study was to determine whether a cordless phone set, MP4 player, FM radio, asymmetric digital subscriber line (ADSL), or a mobile phone could influence the accuracy of working length determination by the Dentaport ZX apex locator. In this study, twenty-four sound intact single-rooted extracted human teeth were used. After determining the root canal length with a file and a microscope, the canals were measured with three separate Dentaport ZX apex locators while one of the test devices (ADSL, MP4, FM radio, mobile phone, and cordless phone) was used at a distance of 50 cm from the apex locator. Bland-Altman plots was used for reliability and consistency. Except for the FM radio, all other devices showed significant difference with actual working length (P<0.05). ADSL and MP4 player showed the least consistency compared to the other devices. Based on this in vitro study, the use of ADSL, MP4 player, mobile phone, and cordless phone during root canal treatment may influence working length determination with the Dentaport ZX apex locator.