Can otoplasty impact hearing? A prospective randomized controlled study examining the effects of pinna position on speech reception and intelligibility

Eighteen adults with normal hearing and pinnae were recruited and the pinna positions were randomized in each participant. Intracanal acoustical analysis was performed to calculate the Speech Intelligibility Index (SII). Hearing In Noise Test (HINT) with two azimuth speaker arrangement was also performed. The outcome measures were compared using paired t-tests for both pinna positions.The SII significantly improved with the pinna in forward position (49.3 vs. 45.8, p<0.001). HINT thresholds also improved with the pinna forward (-6.43dB vs. -5.08dB, p=0.0003).Pinna position affects audiological performance, in both speech intelligibility and speech reception in noise. These are novel findings that may impact the informed consent process and decision to treat for patients undergoing otoplasty.Protruding ears, or prominotia, is the most common congenital deformity of the head and neck, with an incidence as high as 5 percent in certain populations [1]. The specific etiology of the protruding ears is usually due to an underdeveloped antihelical fold and/or conchal bowl hypertrophy [2]. Otoplasty is a surgical procedure, employed primarily in children, that attempts to restore the ideal aesthetic position of the pinna.Many studies have described the “ideal” position of the outer ear [1-4]. In addition, there are several anthropometric studies that document normal auricular dimensions throughout childhood [5-7].Protrusion of the pinna is typically measured along a hypothetical plane drawn from the lateral helical margin to the mastoid scalp. From the scalp, the helical rim at the superior pole normally projects laterally 10 to 12 mm, at the midpoint 16 to 18 mm, and at the lobule 20 to 22 mm [8,9]. The auriculocephalic angle, which is normally less than 35 degrees, has also been used to describe the degree of auricular protrusion [8,10].The pinna is a well-recognized component of the auditory system, with the ability to shape the incoming acoustic signal. Several studies h