|Year : 2018 | Volume
| Issue : 4 | Page : 307-311
Relationship between dominant hand and ear preference for listening among medical students
Sandeep Sachdeva, Nidhi Dwivedi
Department of Community Medicine, North DMC Medical College and Hindu Rao Hospital, New Delhi, India
|Date of Web Publication||2-Aug-2018|
Department of Community Medicine, North DMC Medical College and Hindu Rao Hospital, New Delhi - 110 007
Source of Support: None, Conflict of Interest: None
Objective: The aim of the study was to determine dominant hand for routine activities and ear preference for listening among medical students. Mobile phone usage was also studied. Methodology: Medical students of three batches (2nd, 3rd, and 4th year) studying in a government medical college of Delhi (India) were considered. Out of 150 permitted (50 per batch) seats, only 139 were filled. Thus, after seeking an informed consent, a total of 117 (84.1%) available students could be contacted in person who completed the survey capturing details such as Section-I: Sociodemographic background; Section-II: Dominant hand (right/left) for undertaking routine activities, ear (right/left) preference for listening say mobile phones; and Section-III: Selected details of their mobile phones. Results: There were 71 (60.7%) males and 46 (39.3%) female students; It was found out that out of 117 students, 110 (94.0%) were right handed while 7 (5.9%) were left handed. Out of all the right-handed persons (n = 110), 94 (85.4%) preferred right ear, 14 (12.7%) left ear, and 2 (1.8%) either of the ears for listening phone. Similarly, out of all the left-handed persons (n = 07), 6 (85.7%) preferred left ear and only 1 (14.2%) right ear for listening mobile phone. Right-sided (right hand-right ear) laterality was observed in 85.4% and left-sided (left hand-left ear) laterality in 85.7% with overall (same hand-same ear) laterality of 85.4% among study participants (P < 0.01). Most common color of mobile phone was black (59, 50.4%), white (30, 25.6%), golden (13, 11.1%), silver (6, 5.1%), etc. Average time spent per day by medical students on mobile phones (either communication, Internet/WhatsApp/Facebook, listening songs, playing games, or reading E-books) was 3.83 (±2.1) h and average monthly expenditure on mobile phone was 10% of personal expenditure, i.e., Rs. 532 (±374.4). Conclusion: Our descriptive study reiterates that most participants were right handed (dominant limb) and majority of them preferred right ear for listening phones.
Keywords: Audiometer, auditory, communication, hemisphere dominance, lateralization, phone
|How to cite this article:|
Sachdeva S, Dwivedi N. Relationship between dominant hand and ear preference for listening among medical students. Med J DY Patil Vidyapeeth 2018;11:307-11
|How to cite this URL:|
Sachdeva S, Dwivedi N. Relationship between dominant hand and ear preference for listening among medical students. Med J DY Patil Vidyapeeth [serial online] 2018 [cited 2019 Oct 22];11:307-11. Available from: http://www.mjdrdypv.org/text.asp?2018/11/4/307/238162
| Introduction|| |
Observing normal people reveals that majority (85%) are right handed, some left handed, while the rest are considered ambidextrous, i.e., they can use both the left and right limbs equally. The anatomical and functional asymmetries are linked with individual differences in cerebral organization. Functional asymmetry between two halves of the brain controls the consciousness, memory, speech, intelligence as well as voluntary and involuntary actions, etc., Genetic constitution, education, attitude, culture, social upbringing, and environment influence our personality and mannerism in public arena.
Neuropsychologists have long been interested in handedness as a possible indirect measure of cerebral lateralization. Indeed majority of right-handers have language skills lateralized to the left hemisphere. However, this is also the case for about 67%–85% of left-handers., Even after the development of accurate and reliable neuroimaging methods, hand preference is still often used as a proxy for cerebral lateralization, presumably because it is a cheap and very accessible measure.
Some researchers simply categorized people as left handed or right handed based on the hand used to hold a pen when writing. Quantitative measures to assess handedness include peg moving, finger tapping, or dotting within a boundary and assessed through various inventory methods such as Edinburgh Handedness Inventory; Annett's peg-moving test, and Quantification of Hand Preference (QHP) task.,, The inventory and the QHP task measure preference, whereas the peg-moving task measures relative skill. While the inventory summarizes the consistency of hand preference across different activities, the QHP task uses a behavioral continuum to characterize individual variation in hand preference.
The evidence suggests that the asymmetrical functioning of the two halves of the brain for speech is reflected in unequal perception of words presented dichotically to left and right ears. In normal participants, speech functions will be represented predominantly in the left hemisphere, and the left cerebral dominance will be reflected in a right-ear superiority on the dichotic (simultaneous presentation of different stimuli to the two ears) digits test.
The aim of the study was to assess the relationship between handedness (dominant right/left hand) for undertaking routine activities and ear preference for listening among medical students. Mobile phone was used as an indicator for citing ear preference for listening. In addition, mobile phone usage pattern by medical students was also studied.
| Methodology|| |
A cross-sectional descriptive study was conducted in a government medical college of Delhi, India. Medical students of three batches (2nd, 3rd, and 4th year) were considered and invited to participate during April 2017. Students were briefed about the study objectives, voluntary nature of participation, and confidentiality of data collection. However, none of them declined to participate. Complete enumeration was the sample strategy, and out of 150 permitted (50 students per batch) seats, only 139 were filled. Thus, after seeking an informed consent, a total of 117 (84.1%) available students could be contacted in person who completed the interview survey.
The study instrument was divided into three sections and captured variables such as Section-I: Sociodemographic details; Section-II: Response was elicited to ascertain dominant hand (right/left) for undertaking routine activities, ear preference for listening say mobile phones; and Section-III: Details of their mobile phones – brand, color, usage pattern, monthly expenditure, etc.
There was no missing values or incomplete schedule. The data were entered into Microsoft Excel spreadsheet and analysis carried out using SPSS version 20 (IBM, New York, USA) through descriptive and inferential statistics and considered significant at P < 0.05.
| Results|| |
Out of 117 students, 71 (60.7%) were male and 46 (39.3%) female; average age was 20 (±1.15) years; native place of 77 (65.8%) students was Delhi and rest (34.2%) were from states outside Delhi but within country; 79 (67.5%) students were staying in hostel; 94 (80.3%) students passed their 12th class from private/convent school whereas rest (19.7%) from government school.
It was found out that out of 117 students, 110 (94.0%) were right (dominant) handed while 7 (5.9%) were left handed [Table 1]. Out of all the right-handed persons (n = 110), 94 (85.4%) preferred right ear, 14 (12.7%) left ear, and 2 (1.8%) either of the ears for listening phone. Similarly, out of all the left-handed persons (n = 07), 6 (85.7%) preferred left ear and only 1 (14.2%) preferred right ear for listening mobile phone [Figure 1]. Right-sided laterality was observed in 85.4% and left-sided laterality in 85.7% with overall laterality of 85.4% among study participants. This observation was found to be highly statistically significant (P < 0.01).
|Table 1: Practices among medical students regarding dominant hand for undertaking routine activities and ear preference for listening|
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|Figure 1: Graph depicting strong lateralization between dominant hand and ear preference for listening phones|
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The top five brands of mobile phones used by medical students were Samsung (30, 25.6%), Apple (18, 15.4%), Motorola (15, 12.8%), HTC (8, 6.8%), Xiomi (7, 6.0%), etc., Most common color of mobile phone was black (59, 50.4%), white (30, 25.6%), golden (13, 11.1%), and silver (6, 5.1%), followed by miscellaneous colors. All the students possessed a smartphone; however, their usage of phone varied. [Table 2] depicts frequency and pattern of mobile phone usage among medical students as proportion. Among daily users of mobile phones, 22.0% of students were communicating frequently; 28% were accessing the internet frequently; 34.1% were listening to songs frequently, but only 18.3% and 12.2% were playing games and reading E-books on frequent bases.
|Table 2: Percentage of medical students according to average daily usage pattern of mobile phone use|
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Average time spent per day by medical students on mobile phones (either communication, internet/WhatsApp/Facebook, listening songs, playing games, or reading E-books) was 3.83 (±2.1) h with 95% confidence interval (CI) as 3.3–4.3 h. The average monthly personal expenditure was Rs. 5191.4 (±3207.5) and average monthly expenditure on mobile phone was Rs. 532 (±374.4) with 95% CI of 450.4–614.9 Rs.
| Discussion|| |
Our study primarily focused among young adults on inferring dominant handedness and ear preference for listening. It was found out that of all the participants, 94.0% were right handed while 6% were left handed in terms of dominant hand. Overall right ear preference was noted among 95 (81.1%) participants (among with either of dominant hand). Right-sided (right hand-right ear) laterality was observed in 85.4% and left-sided (left hand-left ear) laterality in 85.7% with overall (same hand-same ear) laterality of 85.4% among study participants. This observation was found to be highly statistically significant (P < 0.01).
The genesis of this study emerged during personal evaluation of an apparently healthy, right handed, ambulatory, average built 45-year-old patient, clerk by profession who presented in outpatient department of our health center. The chief complaints for last couple of months were that he was not comfortable in hearing while placing his phone on the right ear, his usual practice. As a result, he had to repeatedly switch over to the left ear for better audibility. The patient was subsequently escorted to ENT department of our hospital for evaluation and management. External ear, tympanic membrane was normal; however, audiometric investigation was suggestive of age related both sided impairment with profound impairment for high frequency noted in the right ear.
Hemisphere dominance has been a major topic in brain research for over a century. The two hemispheres of the brain are symmetrical in appearance though certain functions are differentially entitled in the two sides of the brain. The structure and function of paired organ or of two similarly organized areas of nonpaired organs, dispersed on the left and right sides, can be referred as laterality. Language dominance refers to the hemisphere of the brain that is primarily responsible for language development, which is the left hemisphere in most people. In right-handers, speech center is located in the left hemisphere in 95% of individuals, while in remaining 5%, it is situated in the right hemisphere. Most people with left brain dominance are right handed. On the corollary, among left-handers, speech center is located in the left hemisphere among 60% individuals, right hemisphere for 20%, and remaining 20% in either of hemisphere.,, In humans, there are four paramount lateral preferences, among which handedness and footedness are concerned with motor functions of limbs and earedness and eyedness with sensory functions. As a population, humans show lateralization with 90% of adults being right handed that is suggestive of genetic predisposition running in families.,
Our data reiterate that most people perform their activities of daily living using their right hand. Of the right-handed people, most held their mobile phones to their right ear, either owing to motor preference of using their right hand or because of an aspect of auditory dominance, a finding that is consistent with other observational studies that most people prefer to listen with their right ear., Similar results were found in preclinical students in a university of Benin, Nigeria. Sociodemography had little bearing on these results. It is reported that having a hearing difference does have an impact on ear preference. First, persons who hear better in their left ear are more likely to use the left ear regardless of handedness. Second, persons who hear equally well in both ears are more likely to use their dominant hand-side ear and the same-side ear. Third, for those who hear better in the right ear, the probability of using the dominant hand side with a cell phone is >50% as in our case. Therefore, preference usage of contralateral ear by a person may suggest hearing impairment in the ipsilateral side requiring audiometric confirmation.
Mobile phone has become a critical element in human life more, so among younger generation due to its diverse functions and utility, it offers to the consumer. Mobile has transformed social practices and changed the way we communicate and do business, yet surprisingly, we have little perception of their effect in our lives. In a study (2015) of mobile usage, among 200 medical students at Kolhapur (Maharashtra, India), it was found that 65.5% were using mobile for >2 h/day; 56.5% were using the mobiles “regularly” during the college hours; 60% of students were spending more than Rs. 200/- per month on mobile phones, etc. In another study carried out (2015) in Banaras (India), majority (41.82%) of medical students were found to be spending between Rs. 200/- and 400/- while about 11% students spent >Rs. 600/month on their phones; 11.2% were always online, etc. In a study carried out (2011) in Puducherry (India), among 309 medical students, average communication time was 59.5 min and 39.8% were frequent caller/receiver per day, etc. The average monthly expenditure among medical students on mobile phone was Rs. 271/- in a medical college of Bhavnagar, Gujarat. In our study sample, average time spent per day by medical students on mobile phones was 3.83 (±2.1) hours; 69.5% of medical students were using mobile for >2 h/day; 54.8% were incurring average monthly expenditure of Rs. 500/- on mobile phones. Some of the students were incurring high personal expenditure including electricity bills for running air-conditioners. Approximately 10% of personal monthly expenditure was incurred on mobile phones. Sociodemography had little statistical bearing on these results also. It is noted that over the years, the utility and dependency of mobile phone is increasing among youth that may have profound adverse health consequences including psychological, visual, and auditory ill-effects.
In conclusion, our study reiterates that of all the participants, 94.0% were right handed while 6% were left handed in terms of dominant hand for undertaking routine activities. Overall right ear preference was noted among 95 (81.1%) participants (among with either of dominant hand); right sided (right hand-right ear) laterality was observed in 85.4% and left-sided (left hand-left ear) laterality in 85.7% with overall laterality (same hand-same ear) of 85.4% among study participants.
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[Table 1], [Table 2]