Age-related auditory disorder is a complex disorder characterized by a decline in peripheral and central auditory and cognitive functions. Hearing thresholds, which begin to be elevated from higher frequencies, vary significantly among the subjects and the speed of the threshold elevation increases with age. Speech perception is affected in subjects with presbycusis, due mainly to their hearing loss, but is more severely so in patients of advanced age. Otoacoustic emissions and auditory brainstem responses are also impaired, mainly reflecting the subjects' hearing threshold elevations, and less significantly, their age. Auditory temporal processing, which can be evaluated by psychoacoustic tests such as the gap detection test, is also deteriorated in elderly subjects. For elderly subjects with difficulty in speech communication in daily life, hearing aid (HA) is the treatment of choice. When HAs no longer provide benefit, cochlear implantation is the treatment of choice; excellent results of cochlear implantation have been demonstrated even in elderly subjects, although those who are older at implantation tend to show lower speech understanding scores postoperatively. It is considered important to avoid unnecessary exposure to loud noises and to prevent/treat atherosclerosis in order to prevent age-related auditory disorder. Auditory-based cognitive training may be useful to restore age-related deficits in temporal processing.
In the present study, 37 patients (22-78 years, 20 males and 17 females) with mild and acute sensorineural hearing loss (ASNHL) were evaluated. All patients met the following criteria: 1) rapid unilateral hearing loss and/or tinnitus, 2) pure-tone average (PTA) at 250, 500, 1000, 2000 and 4000Hz<40dB, and 3) unknown etiology. Patients with acute low-tone sensorineural hearing loss were excluded. The study patients were divided into two groups: 1) patients with an audiometric threshold ≥ 30dB HL in three connected frequencies (group A) and 2) others (group B). Of all the patients, 70% of group A and 79% of group B complained of hearing loss, and 91% of group A and 92% of group B had tinnitus. The most prevalent audiometric configuration was the high-tone type in both groups. In the positional nystagmus test, 26% of group A and 14% of group B complained of vertigo and/or dizziness, while 56% of group A and 36% of group B showed unidirectional nystagmus. The hearing prognosis was judged as “unchanged” in 51% of all patients, suggesting that the prognosis of mild ASNHL was not good. Further studies are needed to clarify the nature of mild ASNHL.
The objective of the present study was to investigate the time taken by patients to hear with and habituate themselves to hearing aids based on our recommendations. We encouraged 25 patients with bilateral sensorineural hearing loss who had never used hearing aids to wear them for as long as they could. As a result, 23 of these 25 patients started using the hearing aids for an average of 11 hours from the next day and were able to use them for more than 11 hours subsequently. One of the two remaining patients who did not purchase the hearing aid, had difficulty in getting habituated. Another patient who did not purchase a hearing aid because of economic reasons was able to use the hearing aids for over 10 hours. We assessed the patients' ability to habituate themselves to hearing aids on a visual analog scale (VAS). The average VAS score was approximately 50 during the first week, 80 in the fifth week, and 90 in the eighth week. On the basis of these scores, we consider that patients require about 2 months to habituate themselves to hearing aids. Prior to this study, we instructed the patients to initially wear their hearing aids for short periods of time. However, the results of this study indicate that patients can habituate themselves to wearing hearing aids for long periods of time.
We report the case of a boy who developed Landau-Kleffner syndrome (LKS) at the age of six years. The disease manifested as language disturbances such as auditory agnosia and slurred speech, along with behavioral disturbances, including concentration difficulties and irritability. Seizures suggestive of epilepsy occurred twice, and the boy was diagnosed as having LKS based on continuous spike waves during sleep recorded on EEG. Although the abnormal EEG normalized during the course of the disease, and the language disturbances, EEG abnormalities and epilepsy improved, the patient continues to manifest mild cognitive impairment of speech recognition, poor vocabulary, and poor expressions. Language training in children with LKS is not easy because of the accompanying auditory agnosia and behavioral disturbances. Although there are no problems in their daily lives, problems inevitably arise as they proceed to higher grades in school where lessons primarily involve abstract and multifaceted thinking. Therefore, it is very important to understand the characteristics and language problems of each child and to provide them with learning education as well as mental health support.
Auditory behaviors and vocalization in children using cochlear implants were evaluated using MAIS and MUSS in the preoperative phase and during twenty-four months of CI use. Thirty-two children who received cochlear implants before the age of four years were enrolled and the following results were obtained. 1) The average scores on MAIS and MUSS showed rapid improvement by three months after the start of CI use. The MAIS scores exceeded the MUSS scores at all the evaluation time-points and the scores on the two scales were highly correlated. 2) The rate of improvement of the MAIS score was the highest after one month of CI use, while that of the MUSS score was highest at three months after the start of CI use (initial improvement period). Individual differences of MAIS scores became minimal by twenty-four months, while those of MUSS increased during the same period. 3) In the initial improvement period, the MAIS scores were higher in the children in whom the language development was better preoperatively and who underwent CI at an older age. Preoperative language development influenced the MUSS scores in the initial improvement period, but no longer exerted influence in the middle improvement period. 4) To predict cochlear implant performance, the middle improvement period is notable the most suitable, at which time the effect of the preoperative status is eliminated, and careful observation is needed.
In this study, we investigated the effects of time-compressed speech for cochlear implant (CI) users and normal hearing subjects (NHs), and also determined the effectiveness of pauses inserted in speech passages clips. Our subjects comprised 13 CI subjects using the Nucleus CI-24 system with the ACE processing strategy, and 10 age-matched and NH adults serving as control subjects. As for the experimental stimuli, sentence test materials were time-compressed to ratios of 0.75 and 0.5 relative to the natural speaking rate, using sound editing software. Furthermore, these time-compressed speech clips were restored to 100% of the original duration by inserting silences at syntactic boundaries and random points in the passage clip. Subjects were instructed to listen to each passage and to recall the sentences aloud as much as possible. Results showed that speech perception scores decreased as the speech rate increased in both CI users and NHs, the tendency being more pronounced in the CI users than in the NHs. In the CI users, time restoration at syntactic points improved the recall performance only for 0.75 time-compressed speech. We suggest that it is important to insert pauses at semantically appropriate points during rapid speech for CI users.