By fourth decade, there is severe hearing loss for mid frequencies and moderate hearing loss for high frequencies (4000-8000 Hz) (U-shaped audiometric profile)
Moreno-Pelayo et al. (2003) reported a large Spanish family in which 14 members over 4 generations were affected with autosomal dominant nonsyndromic sensorineural hearing loss. Onset was in the first decade and was characterized by hearing loss that ... Moreno-Pelayo et al. (2003) reported a large Spanish family in which 14 members over 4 generations were affected with autosomal dominant nonsyndromic sensorineural hearing loss. Onset was in the first decade and was characterized by hearing loss that was moderate for low and mid frequencies and mild for high frequencies (4,000-8,000 Hz). Later, it progressed to moderate hearing loss in the 125-250 Hz and 4,000-8,000 Hz ranges, and to severe in the 500-2,000 Hz range in the fourth decade. Linear regression analysis showed a 0.7 dB/year age-linked progression of the hearing loss at all frequencies. Affected members did not exhibit tinnitus or vestibular dysfunction.