Publication Date


Document Type

Honors Thesis


Mathematics and Statistics


Current diagnostic tools do not provide a reliable test for middle-ear status in infants under six months of age. While tympanometry is used in infants over six months of age, its efficacy in those younger than six months is debatable. Recent work suggests that reflectance may be more reliable than tympanometry for diagnosing and monitoring middle-ear dysfunction in young infants. This work presents reflectance measurements in 8 normal, healthy newborns (age 3 to 7 days) and 11 normal, healthy one-month olds (age 28 to 34 days) with no prior indication of middle or inner ear dysfunction. Normative ranges for both ages are presented, along with assessment of changes between newborns and one-month old infants. Results were compared with the literature-based measurements from the available groups: (1) infants one-month and older, (2) high risk newborns and newborns in a neonatal intensive-care unit, and (3) infants ranging from 3 days to two months of age. In addition, comparisons of left and right ears and gender in both newborns and one-month olds were conducted as some research indicates that there are variations in refl ectance due to these factors. Our specific contribution to this growing normative data set is measurements from separate groups for normal newborns and one-month old infants. Since reflectance has potential to provide clinically useful information starting at birth, it is important to collect data across small early age increments in order to develop accurate normative standards. The measurements collected in this study are similar to other literature-based measurements at most frequencies. Additionally, our results show that at most frequencies there are no differences between healthy newborns and one-month olds. Our results show some differences between left and right ears in newborns between 1195 and 1500 Hz, as well as differences between newborns and one-month olds between 1710 and 2180 Hz and 5390 and 5578 Hz. Overall, our results suggest that normative measurements of ER are similar between our two age groups, and between left and right ears and male and female ears, with no differences at most frequencies.


90 p. : ill. (chiefly col.) Honors project-Smith College, Northampton, Mass., 2009. Includes bibliographical references (p. 64-65)