The authors compared language ability and neuro-psychological cognition in two patients, one (Case A) with a cochlear implant (CI) since 2 years of age, and the other (Case B) with an implant since 6 years of age. The conclusions were: 1) Patient A had suitable or better abilities for chronological age (CA) in the phonological cognition of single-syllables and words, acquisition of vocabulary, and articulation, a higher I. Q. on the Tanaka-Binet Test, V. I. Q. on the WPPSI, and the reading ability in age of 5 years that was the time after 2 years 11 month since he had started wearing the cochlear implant CI. 2) Patient B had a 100% score for abilities in the phonological cognition of single-syllables and words, a suitable I. Q. on the Tanaka-Binet Test, and the reading ability for CA, but she was greatly retarded in acquisition of vocabulary, and articulation, and her V. I. Q. on the WPPSI in age of 7 years that was the time after 1 year since she started wearing the CI. 3) These findings suggested that CIs should be implanted in congenitally children by 2 years of age, when the brain is very pliable.
The present study assessed the psychological profile and daily activities of tinnitus patients by conducting an item analysis of the Tinnitus Handicap Inventory (THI). The subjects comprised 239 tinnitus patients (men, 130; women, 109) who had completed the THI. We examined the percentage of patients who answered ‘yes’ or ‘sometimes’ for all items. We also grouped the patients into three categories (mild, moderate and severe handicap) according to their total THI scores and investigated the percentage of patients who responded ‘yes’ or ‘sometimes’ in each category. Our results showed that most tinnitus patients felt anxious and irritable. Patients with mild handicaps sometimes had difficulty sleeping or concentrating. Patients with moderate handicaps felt depressed and fatigued and could not enjoy life. Patients with severe handicaps were even more depressed and could not maintain good relationships with the members of their family and friends. In other words, tinnitus can generate a disability at a personal level that ultimately produces a handicap at a social level. From these results, we concluded that the THI may be useful for evaluating the psychological profiles and daily activities of tinnitus patients and to determine candidates for treatment.
Digital hearing aids with an adaptive directional microphone system have been recently marketed. They provide optimal SNR (signal-to-noise ratio) performance, because the adaptive directional system can change the polar pattern to match the null (s) in a hearing aid to the direction (s) of the noise source (s). The acoustic characteristics of the system, however, have not been sufficiently investigated. We measured outputs of HATS (Head and Torso Simulator) with commercial hearing aids for each mode (omni-directional and adaptive-directional) by using a moving sound source. Noise suppression by the adaptive directional mode for all hearing aids was markedly superior to the omni-directional mode on the back of the subject and on the same side as the hearing aid was worn. The greatest value of the adaptive directional effect was from 9dB to 18dB across hearing aids, and the characteristics of the adaptive directional effect for 1/3 octave bands frequencies were not the same for all hearing aids. Thus, we need to know the finding that the acoustic characteristics varied depending on the hearing aids which have features similar to those of adaptive directional microphone systems.
Sensorineural hearing loss is commonly accompanied by reduced frequency selectivity and temporal resolution. The reduction of frequency selectivity causes marked disadvantages through masking, particularly masking of middle and high frequency components by intense low frequency components: the so-called upward spread of masking. Splitting the frequency spectrum into two complementary parts to reduce masking between contiguous frequency bands and presenting them dichotically might improve speech intelligibility. We studied sound image localization perceived under dichotic listening conditions. We conducted sound image localization tests using speech samples of daily conversation in six young adults with normal hearing and four elderly persons with impaired hearing. Head-related transfer functions (five directions, non-individualized) were convolved to achieve directivity of the speech samples. The results showed that localization errors varied with the dividing conditions and whether hearing was impaired. The sound image of hearing impaired listeners tended to be located on the side of the low-frequency portion. Normal-hearing listeners tended to perceive two sound images, one of which corresponded to the low-frequency part, and the other to the high-frequency part.