Development of audiometric parameters throughout the lifespan. I: Auditory data

Abstract

Age-related hearing loss (presbycusis) is a nonsyndromic sensorineural condition that affects the inner ear, auditory pathway, and related cortical regions to varying degrees, typically beginning around age 65. However, hearing can start to deteriorate as early as age 18 and can be negatively influenced by several external factors throughout the lifespan. Depending on the location and severity of the pathology, different aspects of hearing may be affected, resulting in various phenotypes of hearing loss. The aim of this study is to determine average data for a complex battery of auditory tests for different age groups along life span. Two hundred ninety (116 males and 174 females) volunteers between 18 and 87 years of age were enrolled in this study. All volunteers underwent meticulous auditory examination on our custom made audiometric device that consisted of following tests: pure tone audiometry (PTA) in quiet and noise (PTAN), high frequency hearing thresholds (PTAhf), detection of short tones (STD), sensitivity to interaural time delay (ITD), sensitivity to amplitude (AMT) and frequency modulation (FMT), gap in noise detection threshold (GDT), identification of frequency (FPT) and duration patterns (DPT), speech audiometry in babble noise (SIN), and gated (interrupted) speech audiometry (GS). The data are presented as group means and standard deviations in six 10-year age categories (from 20 to 80) and also as regression fits along with the corresponding prediction bands. All reported results show a significant effect of aging on examined auditory parameters; however, the effect of aging differs. In following tests, the dependence is continuous and starts relatively early in life: PTA, PTAhf, STD, AMT, GDT, FPT; whereas in following tests the effect of aging becomes apparent only after the age of 60: PTAN, ITD, FMT, DPT, SIN, GS. Altogether, the results demonstrate clear, yet diverse effects of aging on various aspects of auditory processing and provide a baseline for future experimental and clinical investigations.

Keywords: Aging; Auditory functions; Hearing; Population study; Speech comprehension.