BACKGROUND AND OBJECTIVES: With the advent of high speed digital signal processing chips, many digital techniques have been introduced to hearing aids. Generally, subject-based clinical tests are needed to verify the performance of hearing aids, which required both time and cost. A hearing impairment simulation (HIS) system is developed in real-time system which is aimed to simulate the sensorineural hearing impairment. In this paper, we present an indirect method to evaluate and predict the performance of hearing aid systems without the help of actual subjects. MATERIALS AND METHODS: The system is developed based on the model constructed from auditory test results and nonlinear behaviors of sensorineural hearing impaired persons. To verify the proposed system, signals processed were presented to normal listeners and their auditory data modified by the system were measured and compared with those of the impaired models. RESULTS: The auditory data of models were closely simulated to normal listeners by HIS system in all frequencies especially to those with hearing loss of more than 60 dB. CONCLUSION: HIS System can be used clinically in developing new digital hearing aid algorithm.
Computer Systems ; Hearing Aids* ; Hearing Loss* ; Hearing Loss, Sensorineural ; Hearing* ; Persons With Hearing Impairments ; Signal Processing, Computer-Assisted

BACKGROUND AND OBJECTIVES: Hearing impairment is a common problem that increases significantly with age and hearing impaired persons need enough and proper medical and social services. We aimed to assess the present status of hearing rehabilitation services and measure the satisfaction of hearing impaired persons in their living. SUBJECTS AND METHOD: We selected a total of 60 persons by stratified randomized systemic sampling from hearing handicapped persons pre-registered with the Ministry of Health and Welfare. There were 32 males and 28 females with the mean age of 54.0+/-17.7 years. We checked the hearing handicap inventory (HHI), articulation index (AI), and visual analogue scale (VAS) of subjects. RESULTS: From 60 subjects, 35 subjects (58.3%) needed hearing aid and 13 subjects (21.7%) needed cochlear implantation. Thirty six subjects (60.0%) were classified into group 4 and 5 in HHI and the mean VAS score was 4.0+/-2.5. Among the 40 subjects with hearing aid, only 7 subjects (17.5%) had a proper device of hearing rehabilitation. In addition, no subjects had cochlear implantation (CI) even though they needed it. CONCLUSION: From this study, most hearing impaired persons had difficulties in every day living and had emotional problems. The low rate of proper hearing rehabilitation suggested that clinicians have to be concerned about providing hearing rehabilitation and expanding social and medical services for hearing impaired persons.
Cochlear Implantation ; Cochlear Implants ; Correction of Hearing Impairment ; Disabled Persons ; Female ; Hearing Aids ; Hearing Loss ; Hearing* ; Humans ; Male ; Persons With Hearing Impairments* ; Rehabilitation ; Social Work

BACKGROUND AND OBJECTIVES: Although the necessity of hearing aids as one of the rehabilitation methods is increasing, many hearing impaired persons are avoiding the use of behind-the-ear (BTE) hearing aids and prefer the complete-in-the-canal (CIC) hearing aids. CIC hearing aids have cosmetic and acoustic advantages but have problems of acoustic feedback and discomfort in wearing. Changes in the external auditory canal (EAC) by mandibular movements are a primary factor for the acoustic feedback and discomfort. The purpose of this research is to study the pattern of changes in the EAC by mandibular movement using the Korean population as subjects and to get basic data concerning the manufacture of impressions and shells for CIC hearing aids. MATERIALS AND METHODS: Subjects were 19 men with a fit external ear diameter to make CIC hearing aid. Impressions were made by taking 5 different conditions of jaw into consideration : fully opened state, 1/2 opened state, biting state, chewing state and resting state. Impressions were scanned at intervals of O.1mm using a 3D Laser digitizing system. We measured anterior to posterior (AP) width and superior to inferior (SI) height of each impression at the first bend, interbend and the 2nd bend of 5 conditions. RESULTS: Compared with the resting state, statistically significant changes in the AP width of the ear canal were observed at the interbend in the following order : fully opened jaw, 1/2 opened jaw (p <0.05), at 1st bend: 1/2 opened jaw (p<0.05). The 2nd bend biting state showed maximal AP width of the ear canal (p<0.05). The SI height of ear canal revealed statistically insignificant changes. CONCLUSION: We recommend making of ear impressions in the chewing state and shells to be supported at the interbend of the ear canal. The SI dimension of a shell tip should be more ground than AP dimension.
Acoustics ; Ear Canal* ; Ear* ; Ear, External ; Hearing Aids ; Humans ; Jaw ; Male ; Mandible ; Mastication ; Persons With Hearing Impairments ; Rehabilitation

OBJECTIVE: The prevalence of congenital bilateral permanent profound hearing loss in the Philippines is 1.3 per 1000 live births. The prevalence increases to 22 per 1000 live births for unilateral mild to moderate hearing loss. This study was conducted to determine the cost of establishing a universal newborn hearing screening (UNHS) program. Local prevalence data and current costs of screening, diagnostics and intervention strategies for bilateral permanent hearing loss were utilized to estimate the costs of implementing the program.

METHODS: Both short-term and long-term costs for hearing screening centers and for families caring for hearing-impaired children were determined using a societal perspective. Calculations included cost of hearing loss and the effectiveness of testing strategies. In this study the societal cost was considered although some of the costs pertained to costs borne by individual patients or their families since none of the screening, diagnostic and intervention strategies are paid for by insurance companies. An exception is the partial subsidy for cochlear implantation that is reimbursable with the Philippine Health Insurance Corporation.

RESULTS: Using published data on the prevalence of hearing loss and experience from a pilot universal newborn hearing screening project at a national tertiary hospital (Philippine General Hospital), the long-term benefits and savings from UNHS on a national scale greatly outweigh the immediate costs of testing and intervention.

CONCLUSION: The cost benefit of UNHS program at a national level outweighs the financial burden of hearing impaired individuals and their families.

Human ; Male ; Female ; Child ; Infant Newborn ; Cochlear Implantation ; Cost-benefit Analysis ; Hospitals, General ; Hearing Loss ; Hearing Loss, Bilateral ; Persons With Hearing Impairments

OBJECTIVE: To compare the effect of rehabilitation of prelingual deaf children who used a cochlear implant (CI) in one ear and a hearing aids in the opposite ear while the hearing level of the opposite ears are different. Hearing ability, language ability and learning ability was included in the content. The aim of this research is to investigate better style of rehabilitation, and to offer the best help to the prelingual deaf children. METHOD: Accord ing to the hearing level of the ear opposite to the one wearing a cochlear implant and whether the opposite ear wear a hearing aid or not, 30 prelingual deaf children were divided into three groups, including cochlear implant with opposite severe hearing loss and hearing aid ear (CI+SHA), cochlear implant with opposite profound hearing loss and hearing aid ear (CI+PHA), cochlear implant only (CI). The effect of rehabilitation was assessed in six different times (3,6,9,12,15 and 18 months after the cochlear implants and hearing aids began to work). RESULT: The longer time the rehabilitation spends, the better the hearing ability,language ability and the learning ability were. The hearing ability of CI+SHA was better than those of CI+PHA (P<0.05) and CI (P<0.05). The language ability and learning ability of CI-SHA was nearly equal to those of the other two groups. CONCLUSION The prelingual deaf children should take much more time on rehabilitation. The effect of rehabilitation for prelingual deaf children who used cochlear implant in one ear and hearing aid in the other depend on the residual hearing level of the other ear. If a prelingual deaf children still has any residual hearing level in the ear opposite to the cochlear implant ear, it is better for him/her to wear a hearing aid in the ear.
Child ; Child, Preschool ; Cochlear Implantation ; Cochlear Implants ; Deafness ; physiopathology ; rehabilitation ; Female ; Hearing Aids ; Humans ; Male ; Persons With Hearing Impairments ; rehabilitation ; Sound Localization ; Speech Perception ; Treatment Outcome

OBJECTIVE: To analyze the characteristics and development of auditory skill for infants with different age before and after cochlear implantation by using infant-toddler meaningful auditory integration scale (IT-MAIS) questionnaire, and provide the useful information for the criteria of candidacy for cochlear implantation in infants and habilitation after cochlear implantation. METHOD: One hundred and thirty-nine prelingually infants with profound hearing loss were included in this study. According to the age at implantation, the infants were divided into 5 groups. They were group A ( < or =12 months), B (13-18 months), C (19-24 months), D (25-30 months) and E (31-36 months). Audiologists who were trained before this study used the IT-MAIS questionnaire to evaluate the auditory skill for all the infants and asked for the parents' or guardians' answers face to face. All the information about the infants spontaneous auditory behavioural responses was recorded in detail. The evaluation was performed before operation and 1 month, 3 months, 6 months, 12 months after switch-on. RESULT: There were no significant differences in mean scores over time between different gender who received cochlear implants by Independent-Samples T Test (P > 0.05). There were no significant differences in mean scores over time among the 5 groups by Multiple Comparison in ANOVA (P > 0.05). The scores were increased with time and there were significant differences in mean scores among the different time before and after switch-on by Multiple Comparison in ANOVA (P < 0.05) for each group. CONCLUSION The development of the auditory skill for infants followed the same rate in different gender. The auditory skill for infants after cochlear implantation developed rapidly regardless of age at implantation. Most of infants indicated rapid improvement in auditory skill within the first 6 months after switch-on, and then showed relative slow increase in the following 6 months.
Age Distribution ; Auditory Perception ; Child, Preschool ; Cochlear Implantation ; Cochlear Implants ; Female ; Humans ; Infant ; Language Development ; Male ; Persons With Hearing Impairments ; rehabilitation ; Treatment Outcome

OBJECTIVETo detect the GJB2 gene mutation in patients with autosomal-recessive deafness, and analyze the relationship between clinical phenotype and gene mutation.

METHODSForty-two patients were examined clinically by pure tone audiometry, acoustic impedance and auditory brainstem response. The complete coding region of the GJB2 gene was amplified by polymerase chain reaction (PCR) and the PCR products were subjected to automatic DNA sequencing.

RESULTSTwo cases had homozygous mutation of 235delC. One of them had sensorineural hearing loss while the other had mixed hearing loss. Heterozygous mutation of 176del16bp was detected in a pair of twins who had mixed hearing loss. The 109G to A, 79G to A and 341A to G mutations were observed in both the patients and the controls.

CONCLUSIONHomozygous 235delC mutation is one of the pathogeni c mutations which could occur in patients with mixed hearing loss. The heterozygous 176del16bp mutation combined with environmental factor may cause hearing loss. The 109G to A, 79G to A and 341A to G variants were considered to be polymorphisms of the GJB2 gene.

Adult ; Connexin 26 ; Connexins ; genetics ; DNA, Mitochondrial ; Deafness ; genetics ; Female ; Gene Frequency ; Genetic Testing ; Hearing Loss ; genetics ; Hearing Loss, Sensorineural ; genetics ; Humans ; Infant, Newborn ; Male ; Mutagenesis, Insertional ; Mutation ; Persons With Hearing Impairments ; Polymorphism, Genetic ; Sequence Deletion

OBJECTIVE: To investigate the recurrent mutations between Uigur and Han ethnic deaf group in Xinjiang region and determine the relationship between ethnicity and mutations. METHOD: DNA were extracted from peripheral blood of 125 deaf patients from Urumqi and Korla special educational schools in Xinjiang. Audiologic examinations showed that all patients had severe to profound bilateral sensorineural hearing hoss. The coding region of GJB2 gene, SLC26A4 and mitochondrial DNA target fragments were amplified by polymerase chain reaction (PCR). Mutations in GJB2 gene, SLC26A4IVS7-2 A>G, mtDNA 1494C>T and mtDNA1555 A>G were identified by sequencing analysis. RESULT: Allelic Frequency of the GJB2 35delG and SLC26A4IVS7-2 A>G mutations in Han deaf students were 7.4% and 10.1%, respectively, whereas not found in Uigur deaf groups. The difference was statistically significant. We did not find significant differences in GJB2 235 delC, 299-300delAT, mtDNA A1555G and C1494T allelic frequency between Uigur and Han students. CONCLUSION Prevalence of the recurrent mutations between Uigur and Han ethnic deaf group in Xinjiang has a great diversity.
Adolescent ; Asian Continental Ancestry Group ; genetics ; Child ; China ; ethnology ; Connexin 26 ; Connexins ; genetics ; DNA, Mitochondrial ; genetics ; Deafness ; ethnology ; genetics ; Ethnic Groups ; Female ; Gene Frequency ; Genotype ; Humans ; Male ; Membrane Transport Proteins ; genetics ; Mutation ; Persons With Hearing Impairments ; Polymorphism, Genetic ; Sulfate Transporters ; Young Adult