Rajesh Ranjan’s research while affiliated with Manipal Academy of Higher Education and other places

Background The P300 is a late cortical neurophysiological response that can be elicited with auditory and visual stimulation, by presenting the stimuli in an odd-ball paradigm. When deviant stimuli are elicited using auditory stimuli, the P300 is recorded as a large positive peak approximately 300 ms after the stimulus onset in the waveform. Adolescent brain development is heavily influenced by hormonal and physical transitions. Most of the investigations have been done in children and adults, with a limited focus on adolescents. Hence, there is a need to understand the characteristics of P300 in this group. Objective The current research was planned to measure the effect of auditory memory load on speech-evoked P300 in healthy adolescents. Methods A total of 14 late adolescents aged between 18.1 and 24 years participated in the study. The P300 was used to record speech stimuli in N-back (zero-back, one-back, and two-back) tasks using 64 channels. Results There was a significant difference in the latency and amplitude of P300 across the N-back tasks. The mean amplitude of P300 was the highest in a zero-back task and the lowest in a one-back task, and the mean latency of P300 was the lowest in a zero-back task and the highest in a one-back task. Conclusion Prolonged latency and smaller amplitude of the P300 as the N-back difficulty level increased from zero-back to one-back and then two-back tasks in healthy adolescents.

The cognitive ability which was perceived as a constant trait, is now understood to be upgraded by adaptive and extended training. Yoga practices are known to sharpen the intellect and enhance concentration. In the initial period of practicing yoga as an alternative/supporting tool to medical line of treatment, it is essential to investigate effect of yoga on cognitive ability using objective method, in order to establish evidences. Hence, aim of this study was to explore the effect of regular practice of sudarsankriya yoga on auditory event related potential (P300) by recording and comparing peak latency and amplitude. The participants were divided into three groups with Group I and Group II participants practicing sudarsankriya yoga for more than 36 months and less than 36 months respectively. Group III were non-practitioners with no prior practice of any form of yoga. Twenty participants in each group with a total of 60 participants between 40 to 65 years of age were recruited for the study. Results revealed a significant difference for mean latency and amplitude between three groups. Findings of the current study suggest that sudarsankriya yoga practices slows down the process of aging effect or maintains on cognitive ability in adults.

Introduction: Audition is essential for communication, and it is vital for the normal cognitive development of children. Hence, if a child has a hearing impairment, it would significantly impact the child's speech and language development, competence, and emotional wellness. Most children with hearing impairment are advised to go for amplification devices or cochlear implantations for communication through oral modality. There are numerous factors upon which the rehabilitation programs' outcomes depend; one critical aspect that influences habilitation/rehabilitation is parents' knowledge regarding hearing impairment, their attitude towards it, and their practice. Therefore, it needed to assess the parental knowledge, attitude, and practice among parents of children with hearing impairment. Method: The study used a cross-sectional study design and a convenient sampling method to recruit the participants. It was a timebound study; all the cases were recruited as participants during the study period. Results: The developed questionnaire has good reliability and validity. The questionnaire was administered to 38 parents to assess their knowledge, attitude, and practice towards their children's hearing impairment. The study's finding revealed that the overall parental knowledge, attitude, and practice towards their children's hearing impairment was found to be good. Conclusion: The developed questionnaires in Hindi have good reliability and validity to assess parental knowledge, attitude, and practice about hearing impairment among parents of children with hearing impairment.

Background: Hearing impairment is the most common congenital anomaly. It is well known that teachers are the corner pillar for inclusive education. Objective: The study aimed to develop a tool that evaluates awareness, knowledge, and practice about Hearing impairment among Teachers and to validate, and test the reliability of the questionnaire. Methods: A cross-sectional study design and convenient sampling was used to recruit 82 participants. The questionnaire was developed after a familiarity check from Kannada language experts then it was intended for content validation by 6 experts in the field of Audiology. The finalized questionnaire was filled by participants and tested for internal consistency and test-retest reliability. Results: In the current study finalized questionnaire consisted of 50 questions. The scale content validation index (S-CVI) was shown to be good with 0.944 S-CVI. The internal consistency showed moderate-good internal consistency in the independent section and very high overall reliability with a value of 0.898. Further test-retest reliability showed no significant difference (p>0.05) in independent and overall scores of test and retest sessions, respectively. Individual domain and total score intraclass coefficients revealed 'high' test-retest reliability. Conclusion: The currently developed questionnaire in the Kannada language to assess teachers' awareness, knowledge, and practice about hearing impairment showed high reliability and validity, making it an efficient tool to assess the gaps between regular school teachers on children with hearing impairment.

BACKGROUND AND OBJECTIVES: Auditory transduction is the process by which sound is converted to neural impulses to pass via the auditory pathway structures to reach the auditory cortex and for with this auditory physiology oxygenated blood supply is a necessity. SudarshanKriya Yoga (SKY) is known to improve lung functioning and oxygen level in blood circulation. Hence objectives of the present study was to compare the performance of modulation detection threshold, gap detection threshold, pitch discrimination threshold and speech perception in noise among middle aged adults who practice and do not practice SKY. MATERIALS AND METHOD: Middle aged individuals who practiced SKY for a minimum of 1year were considered in the experimental group and who did not practices any form of yoga formed the control group. Auditory processing tests of modulation detection threshold, gap detection threshold and pitch discrimination threshold were assessed along with speech perception in noise. RESULTS: The mean modulation detection threshold and SNR 50 scores showed no significant difference between the groups whereas the pitch discrimination and gap detection thresholds showed a significant difference between the groups. CONCLUSION: SKY has a variable effect on the auditory processing abilities. © 2018, Indian Journal of Public Health Research and Development. All rights reserved.

Introduction: One of the most mystifying problems faced by individuals who are exposed to high levels of noise (either occupational or recreational) is the slow deterioration of hearing that takes place. Evidence from the literature also indicates that noise exposure causes a significant sensory neural hearing loss. Hence we planned to compare the hearing of priests and workers of temples using Pure tone Audiometry and the fine spectral DPOAEs. Method: Twenty three male participants between the ages of 20 to 65 years were included in the study. Group 1 participants worked in the temple premises for more than 5 years and all the individuals had reported to have been exposed to noise during work. Group 2 was not exposed to noise. Results: The temple workers had poor thresholds and significantly reduced SNRs compared to the control group. Conclusions: Temple noise has impact on individuals working in the temple premises presence of NIHL. © 2018, Indian Journal of Public Health Research and Development. All rights reserved.

Introduction: In congenital visual impaired individuals one modality is impaired (visual modality) this impairment is compensated by other sensory modalities. There is evidence that visual impaired performed better in different auditory task like localization, auditory memory, verbal memory, auditory attention, and other behavioural tasks when compare to normal sighted individuals. Objective: The current study was aimed to compare the temporal resolution, frequency resolution and speech perception in noise ability in individuals with congenital visual impaired and normal sighted. Methods: Temporal resolution, frequency resolution, and speech perception in noise were measured using MDT, GDT, DDT, SRDT, and SNR50 respectively. Twelve congenital visual impaired participants with age range of 18 to 40 years were taken and equal in number with normal sighted participants. All the participants had normal hearing sensitivity with normal middle ear functioning. Results: Individual with visual impairment showed superior threshold in MDT, SRDT and SNR50 as compared to normal sighted individuals. This may be due to complexity of the tasks; MDT, SRDT and SNR50 are complex tasks than GDT and DDT. Conclusion: Visual impairment showed superior performance in auditory processing and speech perception with complex auditory perceptual tasks.

The aim of the present study was to develop a questionnaire in Kannada language which assesses the handicapping consequences of dizziness. A cross sectional study design and a convenient type of sampling was used to recruit the participants. A total of 36 participants in age range of (18–60 years of age) who reported to have dizziness or vertigo for at least three months of period and who knew to read and write in kannada language participated. The overall questionnaire was found to have an internal consistency α = 0.935 on cronbach’s alpha test and for test retest reliability (r = 0.988) on intra-class correlation coefficient measure. The present studies provide International Classification of Functioning, Disability and Health based questionnaire in kannada which can be used in the clinical set up to assess the quality of life (QOL) in individuals with Vertigo or Dizziness. It will also help to understand the impact of dizziness on QOL from individual’s perspective.

Level of both ovarian hormones increases from the normal levels during process of pregnancy, which alter functioning of cochlea affecting hearing sensitivity. Then in order to quantitatively monitor minute changes within the cochlea OAE's are used. Therefore present study was undertaken with aim to understand the variations in fine structure DPOAE between the three trimesters of pregnancy. Participants included were healthy pregnant women within the age group of 19 - 40 years. Three groups of 30 women each (n=90), grouped on the basis of their trimester of pregnancy (1st, 2nd, or 3rd) participate in this study. Significant effect were observed on fine structure DPOAE (ripple prevalence, ripple density and ripple spacing) when compared across trimesters of pregnant women. Overall fine structure DPOAE across the three trimesters of pregnancy had effect and these effects were more pronounced in the low frequencies hearing.