2010 Volume 53 Issue 1 Pages 54-61
We report the change over the last 30 years of the age at which infants with hearing loss begin to wear hearing aids.
The subjects were 393 infants fitted with hearing aids at the Ibaraki Medical Center. We divided the period between 1979 and 2008 into five six-year blocks (I: 1979-1984, II: 1985-1990, III: 1991-1996, IV: 1997-2002, V: 2003-2008), and investigated the distribution in the time-blocks of the age at which infants with hearing loss began to wear hearing aids. The results were stratified into two groups; infants with mild-moderate hearing loss (average hearing level<70dB) and infants with severe hearing loss group (average hearing level≥70dB).
The following results were obtained.
1) Mild-to-moderate hearing loss group: During period I (1979-1984), the number of infants under 4 years of age wearing hearing aids was only 15%. Thereafter, the number of infants wearing hearing aids at a young age increased progressively, until the number of infants under 4 years of age and under 2 years of age wearing hearing aids increased to 87%, and 55% during period V (2003-2008).
2) Severe hearing loss group: There was little change in the age distribution from period I (1979-1984) to period IV (1997-2002). During period V (2003-2008), however , the number of infants under 1 year of age wearing hearing aids increased rapidly to 48%.
