01846caa a2200217 4500 210621s9999 xx 000 0 und d 2249-9571 Prawin Kumar Efferent System Activation Using Contralateral Suppression of Distortion Product Otoacoustic Emissions in Individuals with Normal Hearing. 2015 Audiologist Grade I,Indira Gandhi Medical College, Himachal Pradesh University,Shimla,India Lecturer in Audiology,All India Institute of Speech and HearingManasagangothri, Mysore,Karnataka, India 475-481 Volume 5 Issue 8 Efferent system can be activated using a non invasive technique named as contralateral suppression of distortion product otoacoustic emissions (DPOAEs). The present study was taken to estimate the amount of suppression noticed in three different age group (Young, middle & older) individuals in the age range of 17-70 years.The results of the study revealed that there are significant differences for distortion product otoacoustic emission amplitude observed between younger and older age group individuals in absence and presence of noise. However, similar differences were notevident between middle and older age group individuals. Further, there were differences in amount of suppression across different age groups only at 1.5 kHz and 2 kHz. Hence, present study highlights efferent system activation could be partially alike across different age groups Otoacoustic Emission, Noise, Efferent system, Outer Hair cells Vivek Sharma International Journal of Health Sciences and Research https://www.ijhsr.org/IJHSR_Vol.5_Issue.8_Aug2015/70.pdf FJAS FJAS 17661 17661