Gain and feedback problems when fitting behind-the-ear hearing aids to profoundly hearing-impaired children

Previous laboratory studies with severely and profoundly hearing-impaired persons aided with behind-the-ear (BTE) hearing aids have resulted in prediction rules for insertion gain and maximum gain without occurrence of acoustic feedback. The practicability of these findings was investigated in the present field trial with 21 profoundly deaf children fitted with power BTE hearing aids. In dialogue situations without background noise, the gain control settings were in accordance with the insertion gain prediction rule, whereas preferred gain may be 10 dB lower in the presence of noise. Consistent with the prediction rule for maximum gain without feedback and the gain response of the present test hearing aid, we observed oscillation in the high-frequency range in which the children had no remaining hearing. When the high-frequency gain was reduced, sufficient low-frequency gain could be provided without feedback problems.     

Selection of hearing aids for severely deaf children

Procedures are described for selecting the gain and frequency response of hearing aids for deaf children and for evaluating aided hearing. These include a comparison of aided thresholds with the speech spectrum to determine how much of the frequency range is functional for each child. This provides a basis for deciding whether to select an aid having a "conventional" (C) response, which de-emphasises the low frequencies, or a low frequency (LF) response which provides more low frequency gain, although not necessarily low frequency emphasis. It is concluded that, for optical aid fitting, some children require "C" responses for both ears, others "LF" responses for both ears and others a "C" response for one ear and an "LF" response for the other. These three possibilities are all required sufficiently commonly that exclusive use of any one would inevitably result in relatively ineffective amplification for many deaf children.     

The educational settings of profoundly deaf children with cochlear implants compared with age-matched peers with hearing aids: implications for management

The educational settings of 42 implanted profoundly deaf children 3 years after implantation were compared with the respective settings of 635 age-matched severely deaf and 511 profoundly deaf children with hearing aids. All implanted children received their implants before beginning school. The results revealed that 3 years after implantation. 38% (16 children) of the implanted profoundly deaf children attended mainstream schools, whereas 57% (24 children) were in a unit, or special class, in a mainstream school, and 5% (two children) were in schools for the deaf. With regard to the age-matched profoundly deaf children with hearing aids, 12% (63 children) attended mainstream schools, whereas 55% (281 children) were in a unit of a mainstream school, and 33% (167 children) were in schools for the deaf. In the group of age-matched severely deaf children, 38% (239 children) attended mainstream schools, whereas 51% (326 children) were in a unit of a mainstream school, and 11% (70 children) were in schools for the deaf. Statistical analysis revealed a highly significant difference between the educational placement of implanted children and hearing-aided profoundly deaf children (p<0.00001), whereas there was no statistically significant difference between implanted children and hearing-aided severely deaf children. In conclusion, implanted profoundly deaf children who have received their implants before beginning school have the same profile of educational placement as aided severely deaf children rather than aided profoundly deaf children of the same age in the UK. This is likely to have significant implications for the future management of profoundly deaf children and to influence future planning of educational support services.     

Requirements on speech processing hearing aids for the profoundly deaf, some preliminary remarks.

Many severely hard of hearing and profoundly deaf persons seem to get very little help from an ordinary hearing aid. This observation has prompted the development of tactile speech processing aids. These aids should however only be used if it can be shown that the subject has no useful residual hearing. In the case of a profound hearing loss the audiogram might in some cases show tactile sensations in the ear. To get a better estimation of the remaining auditory capacity experiments have been made with frequency discrimination measurements, and with speech tests consisting of rhyming word pairs. Results from these different tests are summarized in relation to an audiogram classification system. Two tactile speech processing aids are described. Evaluation studies with these aids show positive results but these results must be compared with the results that can be obtained with ordinary hearing aids and different types of auditory speech processing hearing aids. The possibility to use extreme auditory recording must also be studied. In this case the transmitted signal is not speech-like and it is possible that this limits their usefulness. Experiments with this type of aids might however give valuable information about how the human perceptual systems process signals derived from the original speech signal.     

Comparison of hearing aids and cochlear implants in profoundly and totally deaf persons

Cochlear implants are increasingly used in the rehabilitation of the profoundly and totally deaf. Usually, insufficient gain of speech discrimination with a powerful conventional hearing aid is considered as a prerequisite for a cochlear prosthesis. With recent improvements of electronic systems, the criterion for this decision may change. To keep pace with the technical progress, a battery of speech sound tests suited for minimal auditory capabilities (MAC-battery) was developed and applied to groups of patients fitted with conventional instruments and with two different types of cochlear implants. Based on the comparison of the MAC-battery results of hearing aid groups, with the average performance of an implanted group, most conventionally fitted regular users of hearing aids should not be considered as candidates for cochlear implantation. The MAC-battery, although not a strictly standardized procedure, is a useful instrument for patient counselling and for the selection of implant candidates.     

Auditory implants and tactile aids for the profoundly deaf

This paper reviews data on speech perception via implanted electrodes and via tactile aids. The two approaches are compared in terms of amount and types of aid provided to communication. Related issues discussed are the performance levels with multi-versus single-channel implants, promontory electrical stimulators versus implants, use of minimal residual hearing, implants for children, and the possible design of complementary systems combining auditory implant and tactile information. The diversity of the test methods and subjects used in implant versus tactile research precludes definitive comparisons of speech perception performance. However, it appears from the available data that, at present and for the foreseeable future, neither approach can provide more than a modest aid to lipreading. Speech reception test results from multichannel-implanted subjects are better, on the average, than for single-channel subjects. However, the best single-channel results are comparable to the best multichannel in tests using simple sentences. There is great variation among subjects with the same implant. Tactile aid performance by highly practiced subjects seems comparable to that of the better implant subjects.     

婴幼聋儿助听器的验配及随诊

成立助听观察室专为双耳感音神经性聋婴幼儿选配助听器,并进行定期调试及康复指导,用声场验配法评估助听效果。结果发现佩戴助听器1～3年后的助听效果较初戴时好,两者之间有显著性差异（P＜0．01）,高频差异更大。表明聋儿听敏度特别是高频部分的听敏度有提高。     

Assessment of basal sound identification skills and communication abilities in profoundly deaf children fitted with hearing aids or a cochlear implant

Basal auditory functions and early verbal communication skills were examined in young, profoundly deaf children with hearing aids or a cochlear implant. The hearing aid users (n = 23) were subdivided on the basis of their (unaided) hearing thresholds into: group A (pure tone average (PTA) at 0.5, 1 and 2 kHz: 90–100 dB HL); group B (PTA: 100–110 dB HL); and group C (PTA > 110 dB HL). All the children with a cochlear implant (n = 20) had a profound sensorineural hearing loss with a PTA that exceeded 120 dB HL. Functional hearing was evaluated by means of basal sound identification. The child’s communication abilities with hearing aids or a cochlear implant were assessed using structured observations on the Scales of Early Communication Skills for Hearing Impaired Children. The basal auditory functions on a sound identification level improved over time in the cochlear implant users and groups A and B. Hardly any improvement was seen in group C. The performance of all the groups (either hearing aid or cochlear implant) on the Scales of Early Communication Skills for Hearing Impaired Children at 6 months after fitting the device and at later evaluations, was close to the average level for their age.     

语前聋患儿一侧人工耳蜗对侧助听器效果分析

目的:通过对人工耳蜗植入对侧耳不同听力损失的患儿联合使用助听器与人工耳蜗语前聋患儿的听觉、语言及学习能力进行评估和比较,探索对患儿更为有效的助听方法,帮助患儿获得最大限度的言语交流。方法:将30例3～6岁语前聋患儿按照植入人工耳蜗对侧耳听力损失程度及是否佩戴助听器,分为一侧人工耳蜗+对侧重度听力损失助听器组(CI+SHA组)、一侧人工耳蜗+对侧极重度听力损失助听器组(CI+PHA组)、单耳人工耳蜗组(CI组)。评估各组在康复3、6、9、12、15、18个月时听觉、语言及学习能力,并记录结果。结果:随着术后康复时间的延长,聋儿听觉、语言及学习能力逐渐提高(P<0.05),CI+SHA组听觉能力优于CI+PHA组及CI组(均P<0.05),语言能力及学习能力无明显差异(P>0.05)。结论:语前聋患儿单耳人工耳蜗植入后,若对侧耳尚有残余听力,佩戴助听器后听觉能力效果显著,长期佩戴有助于患儿的康复。     

Reading skills in Persian deaf children with cochlear implants and hearing aids

ObjectivesReading skills are necessary for educational development in children. Many studies have shown that children with hearing loss often experience delays in reading. This study aimed to examine reading skills of Persian deaf children with cochlear implant and hearing aid and compare them with normal hearing counterparts.MethodThe sample consisted of 72 s and third grade Persian-speaking children aged 8–12 years. They were divided into three equal groups including 24 children with cochlear implant (CI), 24 children with hearing aid (HA), and 24 children with normal hearing (NH). Reading performance of participants was evaluated by the “Nama” reading test. “Nama” provides normative data for hearing and deaf children and consists of 10 subtests and the sum of the scores is regarded as reading performance score.ResultsResults of ANOVA on reading test showed that NH children had significantly better reading performance than deaf children with CI and HA in both grades (P < 0.001). Post-hoc analysis, using Tukey test, indicated that there was no significant difference between HA and CI groups in terms of non-word reading, word reading, and word comprehension skills (respectively, P = 0.976, P = 0.988, P = 0.998).ConclusionConsidering the findings, cochlear implantation is not significantly more effective than hearing aid for improvement of reading abilities. It is clear that even with considerable advances in hearing aid technology, many deaf children continue to find literacy a challenging struggle.     

真耳介入增益法在聋儿助听器验配中的应用

真耳介入增益法是助听器常用的验配方法之一。本文应用 NAL -R、2 / 3增益公式 ,对感音神经性耳聋听力损失程度为严重聋和极度聋的聋儿 ( 1 5人 3 0只耳 ) ,进行了助听器验配 ,并对不同频率上的目标增益值、真耳介入增益值方面进行了比较 ,探索适合于这类患者的最佳预选公式。结果发现助听效果最好的是 2 / 3增益公式 ,助听效果最差的是 NAL-R公式 ,但在应用时要强调个体化。     

Young deaf children with hearing aids or cochlear implants: early assessment package for monitoring progress

BACKGROUND: Very few assessment measures exist for evaluating progress in young deaf children with hearing aids and cochlear implants. OBJECTIVE: To introduce and describe an early assessment package that covers auditory perception, communication/language development, and speech production in very young deaf children. MAIN OUTCOME MEASURES: Seven of the assessment measures (Listening Progress Profile, Categories of Auditory Performance, Tait Video Analysis, Stories-Narratives Assessment Procedure, Profile of Actual Linguistic Skills, Speech Intelligibility Rating, and the Profile of Actual Speech Skills) have been specifically developed at the Nottingham Cochlear Implant Programme, and a further one (Meaningful Auditory Integration Scale) was modified for use within the package. Moreover, two commercially available tests (Pragmatics Profile of Everyday Communication Skills and Preschool Language Scale) are included to complete the package. METHODS: The present paper describes each measure, how to use it, and its time frame. In addition, two case studies demonstrate the usefulness of the package as a whole. RESULTS AND CONCLUSIONS: The Nottingham Early Assessment Package (NEAP) offers a framework with which to assess in young deaf children the use of audition and language and communication in real-life situations. Being simple, reliable, and time effective can be used in everyday clinical practice. NEAP is innovative in design and offers a structured approach to monitor very young deaf children, both in short and long term. In addition, it allows the identification of additional problems and areas of difficulty as well as specific abilities and skills. This enables the clinician to determine appropriate intervention strategies.     

广东地区聋儿助听器验配情况分析

目的：探讨广东省内不同经济发展水平地区聋儿助听器验配特点与社会经济发展水平的相关性.方法：选取广东地区常住居民家庭中首次配戴助听器的聋儿,按其家庭常居住地的社会经济发展水平的差异,分为经济较为发达的珠江三角洲地区（包括广州、深圳、珠海、佛山、东莞、中山）和经济相对欠发达的广东其他地区两大组,分别比较其第1次助听器验配时的年龄及性别比例、耳聋程度和助听器种类（数码/模拟）的选择.结果：①广东地区第1次配戴助听器聋儿的平均年龄为3.82岁,男、女比例为1.47：1,地区间差异不明显;②珠江三角洲地区第1次配机时残余听力听性脑干诱发电位Ⅴ波阈值超过90dBnHL的聋儿比例为86.36%,广东其他地区为93.85%,远比珠江三角洲地区高;③珠江三角洲地区第1次配戴助听器时选择数码助听器的聋儿为75.57%,广东其他地区为65.38%.结论：聋儿助听器验配特点与当地的社会经济发展水平密切相关;广东地区配戴助听器聋儿的男、女性别比例存在巨大差异,有待进一步探讨.     

Auditory development after placement of bone-anchored hearing aids Softband among Chinese Mandarin-speaking children with bilateral aural atresia

Objective

To evaluate auditory developments of Chinese Mandarin-speaking children with congenital bilateral aural atresia after using Bone-anchored hearing aids (Baha) Softband and to compare them with matched peers with normal hearing.

Method

Sixteen patients (age ranging from 3 months to 6 years) with bilateral aural atresia and 29 children with normal hearing (age ranging from 8 months to 6 years) were studied. Auditory development was assessed at three time intervals: baseline, 6 months and 12 months. Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) was conducted for children under 4 years old; Meaningful Auditory Integration Scale (MAIS), Chinese Mandarin lexical neighborhood test (MLNT) and sound field pure tone audiometry (PTA) were used for children of 4–6 years old.

Results

Mean IT-MAIS scores were 41 ± 24%, 60 ± 22% and 73 ± 7%, respectively at three time intervals. Mean MAIS scores were 66 ± 7%, 90 ± 5%, and 99 ± 2%. Mean speech discrimination scores at the three time intervals were 74 ± 19%, 86 ± 16%, and 95 ± 4% with the easy disyllabic (D-E) list; 48 ± 18%, 73 ± 15%, and 81 ± 7% with the hard disyllabic (D-H) list; 55 ± 17%, 74 ± 22%, and 83 ± 14% with the easy monosyllabic(M-E) list; and 31 ± 14%, 61 ± 15%, and 71 ± 13% with the hard monosyllabic (M-H) list.

Conclusions

Baha Softband is suitable for infants and young children with bilateral atresia. Results from these auditory development testing are encouraging. Baha Softband should be used as a bridge for surgical implantations when the temporal bone is thick enough.     

Clinical results with a hearing aid and a single-channel vibrotactile device for profoundly deaf adults

The speech perception of a group of 19 adults with post-lingual profound to total hearing loss was tested with nine closed-set speech tests without lipreading, two open-set tests without lipreading and two open-set speech tests with lipreading. The subjects were all prospective cochlear implant patients participating in a clinical trial of the implant and the results reported here were obtained as part of the pre-operative assessment. They were divided into groups on the basis of their prior experience with the aid(s), their speech detection thresholds with the two aids and their personal preferences. Seven of the subjects used a hand-held single-channel vibrotactile device and the other 12 used a powerful conventional hearing aid. Subjects from each group scored significantly better than chance on the closed set tests without lipreading. Training or regular hearing aid use was correlated with good performance on the closed-set tests. No subject showed a significant improvement of the lipreading score when the aid was used as a supplement. The use of sophisticated wearable tactile devices and extensive training may allow a better result, but in this clinical program, neither a hearing aid nor a single-channel vibrotactile device greatly benefited the postlingually profoundly deaf adults.