The bone-anchored hearing aid (BAHA) is surgically implanted into the temporal bone behind the ear in patients with conductive hearing loss or mixed hearing loss, when middle ear surgery or conventional hearing aids are not feasible. Many reports of the results of questionnaire surveys have indicated significantly superior subjective improvement with bone-anchored hearing aids as compared with that obtained with conventional hearing aids. However, there have been no reports of objective evaluation yet as speech tests in quiet and noisy environments were not yet sensitive to detect the significant improvement, because the evaluation methods and test conditions were not unified. Recently, an indication for the application of BAHA in patients with single-sided unilateral deafness has been developed. The potential benefits indicated were the improved hearing in noisy conditions and elimination of the head shadow effect. The patients with unilateral deafness were very satisfied with the BAHA results. Although many reports showed poor sound localization with the use of the BAHA, the testing paradigm does not a testing paradigm cannot replicate real-life experiences. Further studies to evaluate sound localization in this patient population will be required.
Monaural speech recognition thresholds (SRTs)for single digits of the 67-S speech audiometric test list were measured in 30 normal-hearing listeners wearing circumaural (SENNHEISER HDA 200), insert (EAR TONE 3A) or supra-aural (Rion AD-02) earphones, in order to determine the reference level for the first 2 types of earphones. The SRT of the last earphone was measured as control. Data were collected using a within-subject design, in which each subject was tested using the different earphones, the sequence of use being counter-balanced. But, as, during the process of data analysis, a sequencing effect of lower SRTs in the second or the third measurement was partially observed, we reanalyzed the data using a between-subject design with 3 groups consisting of 10 subjects each who were tested using each earphone for the first time. The mean SRTs in the 10 subjects for the circumaural and insert earphones were 8.9 and 9.1dBSPL, respectively, whereas the mean SRT for the supra-aural earphone was 13.7dBSPL, which almost corresponds to the 14dBSPL already established as the reference level. When estimated from the reference internal noise spectrum levels, audible portions of the speech spectrum at the SRT levels for each earphone obtained in this study were similar, which seems to validate our results. To establish the reference SRT levels for the two earphones, it is necessary to collect further data using an independent-group design with a larger number of test subjects and participation of test facilities.
Hereditary hearing loss is the most frequent cause of congenital sensorineural hearing loss (SNHL), and advances in genetic testing have revealed various phenotypes of SNHL according to each gene mutation. On the other hand, clinical examinations, such as a history of development, family history, and various kinds of auditory examinations are also required for the diagnosis of hereditary hearing loss. In this paper, we reviewed 64 patients with bilateral congenital SNHL who visited Iwate Medical University between 1997 and 2007. Genetic testing (GJB2, SLC26A and mt. A1555G mutations) revealed 11 (17.2%) patients with positive results for genetic mutation: 9 with GJB2 mutation and 2 with SLC26A4 mutation. Among these 11 patients, 5 had a negative family history. Patients with hereditary hearing loss increased from 24 patients (37.5%) diagnosed by family history to 29 patients (45.3%) diagnosed by additional genetic testing. Furthermore, audiograms were found to be symmetrical in 10 of the 11 patients (90.9%) with GJB2 or SLC26A4 mutation.
In this study, we measured the equivalent continuous sound pressure level (LZeq) and equivalent A-weighted continuous sound pressure level (LAeq) during conversational Japanese speech. Measurements were made simultaneously at a distance of 1m in front of the subject's lips and near the subject's outer ear canal, in an anechoic room. Data were obtained from twenty subjects (ten females and ten males). The average LZeq was about 60dB in front of the subject's mouth and 74dB near the outer ear canal. The average LAeq was about 56dB in front of the subject's mouth and 69dB near the outer ear canal. The level difference between the average LZeq and average LAeq was about 4dB. The present results might be useful for establishing test conditions for hearing aid evaluation, as well as for investigating possible damage to the hearing organ in the case of over-amplification in wearers of hearing aids during speech.
We encountered examples of hearing-impaired infants wearing hearing aids in whom the result of the newborn screening test for hearing had been “Pass”. Out of 112 infants covered in the study, 60 had undergone the screening test. The result was “Pass” in 10 of these infants, which was 8.9% of total number of infants covered in the study, and 16.7% of the total number of infants who had been subjected to screening. As compared to the findings in the infants who were referred or the infants who had not undergone the risk-free screening test, the first medical examination and age at the start of use of hearing aids was significantly higher in the infants who had passed the test. In regard to the infants who had passed the screening test, it can be said that neither the parents nor the persons involved in the testing appeared to have sufficient understanding, which led to delayed detection of the hearing impairment in these infants. Moreover, in infants at the risk of familial deafness, the screening result was preferred over the risk. In regard to handling of infants at a risk of familial deafness or explanation for infants who had passed the screening test, it is necessary to consider ways to improve the screening method.
We investigated 222 infants who visited the National Mie Hospital for hearing examinations between 2000 and 2008. In 49 (22.1%) cases suspected to have hearing impairment by general health examinations or their parents, six had moderate or severe hearing impairment and two had unilateral hearing loss. The median age at the first visit was four months old. Ninety-five (42.8%) cases were referred to us for advanced hearing examinations after undergoing newborn hearing screening (NHS). The median age at the first visit was one month old. Advanced examinations revealed that 17 had severe, 14 had moderate, 3 had mild and 35 had unilateral hearing loss. In five cases, repeated examination showed improvement of the impaired hearing level to the normal range. The screened children with severe and moderate hearing loss, the average age at the start of use of the hearing aids was 6.8 and 14.8 months, respectively. Although NHS is effective for early detection of mild-to-severe and unilateral hearing loss, sometimes appropriate fitting of hearing aids is difficult, especially in infants with mild-to-moderate hearing loss . It is necessary to design a universal system for NHS and undertake early intervention in children with mild-to-severe hearing loss.
We performed a multicenter clinical study to compare the efficacy of bone-anchored hearing aid (BAHA) with that of conventional air- or bone- conduction hearing aids by means of the APHAB questionnaire survey of patients at 9 hospitals between 2006 and 2008. In all, 26 patients with mixed or conductive hearing loss (including 16 using air-conduction hearing aids and 10 using bone-conduction hearing aids) and 3 patients with unilateral inner ear deafness (including 2 using an air-conduction hearing aid and 1 using a bone-conduction hearing aid) were provided with BAHAs. The questionnaire was administered 1-4 weeks before the surgery and after 12 weeks of experience with the BAHAs. The scores for the communication subscales (ease of communication, background noise, and reverberation), satisfaction, and usefulness on the APHAB were higher with the BAHAs, while the score for the aversiveness subscale was lower. Thus, BAHAs represent a good alternative for conventional air- or bone-conduction hearing aids if the efficacy of the conventional hearing aids is ambiguous.
The administrative office of health and welfare in Tottori Prefecture has played a valuable role in establishing a workable Newborn Hearing Screening (NHS) program, by collaborating with obstetricians, ear- nose- throat (ENT) doctors, pediatricians, public health nurses (PHNs), and teachers of the School for the Deaf. The office made a handbook of the NHS program in 2004, and has been collecting reports on NHS yearly from the concerned people since 2005. In 2008, 4,851 out of 5,527 newborns (87.8%) underwent NHS, and 24 (0.5%) babies were reported to be referred for further evaluation by obstetricians. Twenty-two were reported to have been referred for further examination by ENT doctors. Eight of the children were diagnosed to have normal hearing (false positive rate, 36.4%). Five children with, bilateral hearing loss and 7 with hemilateral hearing loss were detected through the NHS program. Education for the hearing-impaired is being started much earlier than before. Three mothers consulted PHNs about their anxiety and suspicion regarding hearing impairment in their babies. The NHS program in Tottori has been successfully established, although there may be some dropouts among the referred cases, because the numbers reported by obstetricians and ENT doctors were different. To improve the program, it is important to continue to collect and periodically analyze the reports of NHS.