Distortion-product otoacoustic emission components in children exposed to passive smoking

• Grant number: 17/25548-0
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2018
• End date: February 28, 2023
• Field of knowledge: Health Sciences - Speech Therapy
• Principal Investigator: Alessandra Spada Durante
• Grantee: Alessandra Spada Durante
• Host Institution: Faculdade de Ciências Médicas da Santa Casa de São Paulo (FCMSCSP). Fundação Arnaldo Vieira de Carvalho. São Paulo , SP, Brazil
• Associated researchers: Sumitrajit Dhar

Abstract

Whether the auditory periphery is mature at birth and when it starts to decline withage is still an unanswered question in humans, especially when there are conditions that are associated with auditory risk factors.In the present study we are particularly interested in the auditory risk regarding theexposure to passive smoking. The vulnerability of the auditory system to tobaccosmoke is evident and the exposure to second-hand smoke during childhood hasbeen established as a risk factor for hearing loss (Fabry et a., 2011). We havepreviously reported a markedly reduced otoacoustic emissions response level inthe exposed children (Durante et a., 2013), which is consistent with other reports inneonates (Korres et al., 2007; Durante et al., 2011).The present investigation will contribute to the characterization of the behavior ofdistortion product otoacoustic emission (DPOAE) components in a group ofnormal-hearing subjects between the ages of 0 and 10, with and without passivesmoking exposure, with extended f2 frequencies up to 10 kHz.Methods: DPOAEs will be recorded from 100 normal-hearing participants (age 0-10 years) for fixed f2 between 0.75-10 kHz using the primary levels (L1/L2= 55/40dB FPL). Stimuli will be calibrated in terms of forward pressure level (FPL) at theeardrum. F1 will be swept over a range of f2/f1 ratios from 1.05 to 1.5 for each f2frequency. Total DPOAE levels will be estimated using the least squares fitmethod, and DPOAE components will be separated using an inverse-FFT method.Sharpness of tuning (Qerb) will be determined by dividing the best DPOAEfrequency by the bandwidth of a rectangular filter that passes the same total poweras the DPOAEgen filter. Linear regression analyses will be performed to examinefrequency and group effects on DPOAE components.The hypothesis of this project is that DPOAEs components are differently affectedby exposure to smoking in children. The results could help to understand thecochlear function due to the presence of passive smoking exposure according toage. (AU)