Sound Localization Test in Presence of Noise (Sound Localization Test) in Adults without Hearing Alteration

Abstract Introduction Even people with normal hearing may have difficulties locating a sound source in unfavorable sound environments where competitive noise is intense. Objective To develop, describe, validate and establish the normality curve of the sound localization test. Method The sample consisted of 100 healthy subjects with normal hearing, > 18 years old,who agreed to participate in the study. The sound localization testwas applied after the subjects underwent a tonal audiometry exam. For this purpose, a calibrated free field test environment was set up. Then, 30 randompure tones were presented in 2 speakers placed at 45° (on the right and on the left sides of the subject), and the noise was presented froma 3rd speaker, placed at 180°. The noise was presented in 3 hearing situations: optimal listening condition (no noise), noise in relation to 0 dB, and noise in relation to - 10 dB. The subject was asked to point out the side where the pure tone was being perceived, even in the presence of noise. Results All of the 100 participants performed the test in an average time of 99 seconds. The average score was 21, the medium score was 23, and the standard deviation was 3.05. Conclusion The sound localization test proved to be easy to set-up and to apply. The results obtained in the validation of the test suggest that individuals with normal hearing should locate 70% of the presented stimuli. The test can constitute an important instrument in the measurement of noise interference in the ability to locate the sound.

Current Developments and Challenge of Implantable Bone Conduction Hearing Aids / 대한이비인후과학회지

It is acknowledged that implantable bone conduction hearing aids such as a bone anchored hearing aid provide benefit and satisfaction to patients with unilateral hearing loss in terms of sound localization and speech perception under noise circumstances. This review paper introduces current models of the implantable bone conduction hearing aids, their candidacy, brief surgical procedures, and general audiological examinations. A table summary was used for nine published research papers which have very similar results by three points, i.e., no change in ability of sound localization, better performance of Hearing-In-Noise Test, and improved satisfaction of sound quality using questionnaires after the implantation. Unfortunately, systematic fitting strategy for users of the implantable bone conduction hearing aids has not been either studied or developed yet. Futhermore, there is no scientific based approach of reason why the implantation has no benefit in sound localization but still provides better performance for speech perception in noise. In conclusion, specific and effective fitting strategy of the current implantable bone conduction hearing aids should be developed and also support effect of the implantation with sensitivity and specificity for both clinicians and patients while accompanying their advanced technology.

A Method of Evaluating the Horizontal Sound Localization Ability in Normal Children Aged 1~3 Years Old / 听力学及言语疾病杂志

Objective To explore a method of detecting the horizontal localization ability in normal children aged 1~3 years old, and to obtain the minimum audible angle (MAA) at horizontal 0° degree in these children.Methods Using minimum audible angle measure procedure on the basis of conditioned play audiometry and behavioral audiometry methods, sound localization test at horizontal 0° degree was conducted in 37 children aged from 1 to 7 years old with stimulus of different frequencies.Results All 37 children completed the 1 000 Hz tests, 35 children completed the 500 Hz tests, and 30 children completed the 4 000 Hz test.An analysis of 30 children who completed all the tests was performed, 15 of them aged 1~3 years old and the rest aged 4~7 years old.The results for children aged 1~3 years old were as below: 1 000 Hz MAA(0°) =3.57°±1.35°,500 Hz MAA(0°) =5.03°±2.96°,and 4 000 Hz MAA(0°) =5.4°±2.86°, respectively.The results for children aged 4~7 years old were as below: 1 000 Hz MAA(0°) =3.56°±1.48°,500 Hz MAA(0°) =3.5°±2.17°,and 4 000 Hz MAA(0°) =6.13°±4.09°, respectively.There was no significant difference in MAA (0 °) at corresponding frequencies between the two groups.For the children aged 1~3 years old, there was no significant difference in MAA (0 °) among 500 Hz, 1 000 Hz and 4 000 Hz frequencies.For the children aged 4~7 years old, there was significant difference in MAA(0 °) between 500 Hz and 4 000 Hz as well as between 1 000 Hz and 4 000 Hz frequencies.However, there was no significant difference in MAA (0 °) between 500 Hz and 1 000 Hz frequencies.Conclusion MAA test procedure on the basis of conditioned behavioral audiometry and play audiometry could be used to evaluate the ability of sound localization in 1~3 years old children.The frequencies may have effects on children''s sound localization test results and there was no significant difference in MAA (0 °) between the 1~3 years old group and the 4~7 years age group.

Evaluation of the modified test system for children sound localization / 中华耳鼻咽喉头颈外科杂志

Objective@#To evaluate the feasibility of modified test system for sound localization (SL) in children.@*Methods@#Modified system (6 male, 9 female) and traditional method ( 5 male, 5 female) were used for evaluation of minimum audible angle(MAA) and root-mean-square error(RMS) error of 4 to 6 years old children, and the results were compared to verify the accuracy and effectiveness of the modified test system for children sound localization.SPSS 17.0 software was used to analyze the data(t test).@*Results@#(1) Comparison of veracity of modified system and traditional test: when tested at the positive front position using modified system, MAA and RMS error were(3.23±1.00)° and (13.68±5.18)° respectively.When using traditional method, MAA and RMS error were(3.17±0.59)°and (13.96±4.56)° respectively. No statistical differences were found between two groups(t value was 0.16, -0.14, both P>0.05). (2) Comparison of time used were as followed: when using modified system, it was (14.67±1.95) min for MAA, and (6.67±1.35) min for RMS error. When using traditional method, it was (36.30±6.81) min for MAA, and (21.00±3.50) min for RMS error. Time used were significant shorter in modified system than in traditional method (t value was-9.78, -12.37, both P<0.05).@*Conclusion@#Modified test system for children sound localization is useful and reliable in children′s horizontal SL test.The time used of modified test system is shorter than that of traditional test system.

Advances in effect of unilateral auditory deprivation on sound localization / 中华耳鼻咽喉头颈外科杂志

In patients with single-sided deafness (SSD), the interaural time difference and the interaural level difference signals are insufficient or missing, which result in the lack of sound localization ability and the decrease of speech comprehension in the noise environments. SSD can also cause the morphological and functional changes of the central auditory system, resulting in auditory deprivation. In early stage of the development, the auditory center is more susceptible to ambient environment and auditory inputs. It is a critical period of auditory function and morphological refinement. It is also sensitive period of central adaptability after auditory deprivation. SSD in the sensitive period of development can cause significant laterality activities of bilateral sound localization pathway. Unilateral auditory deprivation can distort tonotopic maps, disrupt the binaural integration, reorganize the neural network and change the synaptic transmission in the primary auditory cortex or sub cortex. In order to compensate for the deficiency of the interaural time difference and interaural level difference cues, the auditory pathway is used to improve the ability of sound source localization by using the spectral-shape cues remaining unchanged. In order to improve the effectiveness of the functional areas of the cortex, auditory center is also reorganized by cross-modal. However, central compensation after SSD is a double-edged sword. If SSD onset in the sensitive period, the laterality of auditory pathway will be continued and difficult to reverse by even long term bilateral hearing in the post-sensitive period. Therefore, in order to improve the understanding of the characteristics of unilateral auditory deprivation, this paper reviewed the evidence for adaptive changes in spatial hearing following a developmental hearing loss in one ear.

Validation of the Korean Version of the Spatial Hearing Questionnaire for Assessing the Severity and Symmetry of Hearing Impairment

PURPOSE: Spatial hearing refers to the ability to understand speech and identify sounds in various environments. We assessed the validity of the Korean version of the Spatial Hearing Questionnaire (K-SHQ). MATERIALS AND METHODS: We performed forward translation of the original English SHQ to Korean and backward translation from the Korean to English. Forty-eight patients who were able to read and understand Korean and received a score of 24 or higher on the Mini-Mental Status Examination were included in the study. Patients underwent pure tone audiometry (PTA) using a standard protocol and completed the K-SHQ. Internal consistency was evaluated using Cronbach's alpha, and factor analysis was performed to prove reliability. Construct validity was tested by comparing K-SHQ scores from patients with normal hearing to those with hearing impairment. Scores were compared between subjects with unilateral or bilateral hearing loss and between symmetrical and asymmetrical hearing impairment. RESULTS: Cronbach's alpha showed good internal consistency (0.982). Two factors were identified by factor analysis: There was a significant difference in K-SHQ scores for patients with normal hearing compared to those with hearing impairment. Patients with asymmetric hearing impairment had higher K-SHQ scores than those with symmetric hearing impairment. This is related to a lower threshold of PTA in the better ear of subjects. The hearing ability of the better ear is correlated with K-SHQ score. CONCLUSION: The K-SHQ is a reliable and valid tool with which to assess spatial hearing in patients who speak and read Korean. K-SHQ score reflects the severity and symmetry of hearing impairment.

Cochlear Implantation and Single-sided Deafness: A Systematic Review of the Literature

Introduction Current data show that binaural hearing is superior to unilateral hearing, specifically in the understanding of speech in noisy environments. Furthermore, unilateral hearing reduce oné s ability to localize sound. Objectives This study provides a systematic review of recent studies to evaluate the outcomes of cochlear implantation in patients with single-sided deafness (SSD) with regards to speech discrimination, sound localization and tinnitus suppression. Data Synthesis We performed a search in the PubMed, Cochrane Library and Lilacs databases to assess studies related to cochlear implantation in patients with unilateral deafness. After critical appraisal, eleven studies were selected for data extraction and analysis of demographic, study design and outcome data. Conclusion Although some studies have shown encouraging results on cochlear implantation and SSD, all fail to provide a high level of evidence. Larger studies are necessary to define the tangible benefits of cochlear implantation in patients with SSD.

Measurement of Auditory Discrimination using the Mismatch Negativity (MMN) for the Healthy Youth in the Horizontal Plane / 听力学及言语疾病杂志

Objective To explore whether the changes of sound source in the horizontal azimuth can induce mismatch negativity (MMN) ,and quantify the minimal audible angle which could elicit the MMN and to find effec‐tive way to test human's ability of sound localization in the horizontal plane .Methods With the self developed sound localization device and Bio - logic auditory evoked potentiometer ,in the free field hearing tests were performed on 30 healthy young volunteers according to oddball stimulation sequence .We adopted 1 000 Hz pure tone as the stand‐ard stimuli , the change of sound source location as experimental models ,using minimum audible angle (MAA ) measure procedure ,sound localization test was conducted at 0° ,± 45° ,± 90°standard positions in the horizontal plane .MMN was obtained by subtracting the ERP of deviant stimuli from the ERP of standard stimuli .The latency and amplitude of each MMN were recorded .Results The MMAs of normal young people were recorded and normal values of latency and amplitude of MMN were obtained .The results of the sound localization test for the youth were :MAA(0°)= 2 .09 ± 1 .81° ,MAA( - 45°)= 3 .84 ± 1 .61° ,MAA (45°) = 3 .69 ± 2 .39° ,MAA ( - 90°) = 4 .41 ± 1 . 41° ,MAA(90°)= 4 .23 ± 3 .22° ,separately .There was a significant effect of the location of the deviant stimulus , with those presented at 90° eliciting larger peaks and longer latency period than those presented at 0° .Conclusion Our findings suggest that changes of sound position in the horizontal azimuth can induce mismatch negative waves , and MMN on the basis of MAA test procedure could be used to evaluate the ability of sound localization .

Sound localization and occupational noise

OBJECTIVE: The aim of this study was to determine the effects of occupational noise on sound localization in different spatial planes and frequencies among normal hearing firefighters. METHOD: A total of 29 adults with pure-tone hearing thresholds below 25 dB took part in the study. The participants were divided into a group of 19 firefighters exposed to occupational noise and a control group of 10 adults who were not exposed to such noise. All subjects were assigned a sound localization task involving 117 stimuli from 13 sound sources that were spatially distributed in horizontal, vertical, midsagittal and transverse planes. The three stimuli, which were square waves with fundamental frequencies of 500, 2,000 and 4,000 Hz, were presented at a sound level of 70 dB and were randomly repeated three times from each sound source. The angle between the speaker's axis in the same plane was 45°, and the distance to the subject was 1 m. RESULT: The results demonstrate that the sound localization ability of the firefighters was significantly lower (p<0.01) than that of the control group. CONCLUSION: Exposure to occupational noise, even when not resulting in hearing loss, may lead to a diminished ability to locate a sound source. .

Habilidades auditivas e medidas da imitância acústica em crianças de 4 a 6 anos de idade / Auditory abilities and acoustic immittance measures in children from 4 to 6 year old

OBJETIVO: avaliar o desempenho em habilidades auditivas e as condições de orelha média de crianças de 4 a 6 anos de idade. MÉTODO: foram aplicados os testes de detecção sonora (audiômetro pediátrico em 20dBNA), a Avaliação Simplificada do Processamento Auditivo (ASPA) e as medidas de imitância acústica (handtymp com tom de 226Hz) em 61 crianças com média de idade de 5,65 anos. Para comparar os resultados das provas de habilidades auditivas e das medidas da imitância acústica foi aplicado o teste exato de Fisher com nível de significância de p< 0,05. RESULTADOS: houve alteração em pelo menos uma das habilidades auditivas investigadas em 24,6% das crianças. Houve alteração timpanométrica em 34,4% das crianças e 64% foram classificadas no critério "falha" para a pesquisa do reflexo acústico ispilateral. As crianças mais jovens apresentaram maior ocorrência de alterações de orelha média, mas não houve diferença estatisticamente significante entre as diferentes idades para as provas realizadas. CONCLUSÃO: as crianças mais jovens apresentaram maior ocorrência de alterações nas provas de habilidades auditivas e nas medidas de imitância acústica. Programas de investigação e acompanhamento das condições de orelha média e das habilidades auditivas em idade pré-escolar e escolar podem eliminar ou minimizar intercorrências que alterariam o desenvolvimento sócio-linguístico.

PURPOSE: to evaluate the performance of auditory abilities and conditions in the middle ear of children from 4 to 6 year old. METHOD: we applied the tests in order to detect sound (pediatric audiometer in 20dBHL), the Simplified Assessment of Auditory Processing (SAAP) and the acoustic immittance measures (handtymp with a probe of 226Hz). In order to compare the results from the tests of auditory abilities and measures of acoustic impedance we applied Fisher's exact test with significance level of p <0.05. RESULTS: the study involved 61 children with a mean age of 5.65 years. There was some alteration in at least one of the investigated auditory skills in 24.6% of the children. Tympanometry was altered in 34.4% of the children and 64% were classified on the "fail" criterion for the measure of ipsilateral acoustic reflex. Younger children had higher incidence of middle ear disorders, but with no significant statistical difference between different ages as for the tests. CONCLUSION: younger children showed a higher occurrence of alterations in the tests of auditory abilities and measures of acoustic immittance. Research and monitoring programs for the conditions of the middle ear and auditory skills in preschool and school age can eliminate or minimize events that would alter the socio-linguistic development.

Processamento auditivo na perda auditiva unilateral: relato de caso / Auditory processing in unilateral hearing loss: case report

A perda auditiva unilateral representa grande risco para o atraso acadêmico, a comunicação, o desenvolvimento social e também para o processamento auditivo. Assim, o objetivo deste estudo foi avaliar as habilidades auditivas de localização, fechamento, figura-fundo, resolução temporal e ordenação temporal simples de um sujeito do gênero masculino, 17 anos de idade, com diagnóstico de perda auditiva sensorioneural unilateral de grau profundo, de causa idiopática, sem outros comprometimentos. O processo de avaliação constituiu da aplicação de um questionário, da realização da avaliação audiológica clínica convencional (audiometria tonal, logoaudiometria e imitanciometria) e de testes de processamento auditivo monóticos (SSI ipsilateral, Teste de fala filtrada) e dióticos (Localização sonora, Memória auditiva para sons verbais, Memória auditiva para sons não verbais, AFT-R). Apenas o teste de Localização sonora apresentou resultados alterados. Não foram relatadas queixas relacionadas à habilidade de localização sonora, atenção, discriminação e compreensão auditiva. No caso em estudo, a perda auditiva sensorioneural unilateral de grau profundo não pareceu restringir o desenvolvimento das habilidades do processamento auditivo avaliadas, exceto no que se refere à localização da fonte sonora.

Unilateral hearing loss represents great risk to academic backwardness, communication, social development, and also to auditory processing. Thus, the aim of this study was to evaluate the auditory abilities of localization, closing, figure-ground, temporal resolution, and simple temporal ordering in a male 17-year-old individual diagnosed with profound unilateral sensorineural hearing loss of idiopathic etiology, without other alterations. The evaluation process consisted on the application of a checklist, and the conduction of conventional clinical audiological evaluation (pure-tone audiometry, logoaudiometry, and tympanometry), and of monotic (ipsilateral SSI, Filtered speech test) and diotic (Sound localization, Auditory memory for verbal and non-verbal sounds, AFT-R) auditory processing test. Results showed alteration only in the sound localization test. No complaints were reported regarding the abilities of sound localization, attention, discrimination, and comprehension. In this case study, the profound unilateral sensorineural hearing loss did not seem to restrict the development of the auditory processing abilities evaluated, except for the localization of the sound source.

Otite média recorrente e habilidade de localização sonora em pré-escolares / Otitis media and sound localization ability in preschool children

OBJETIVO: comparar o desempenho de 40 pré-escolares no teste de localização sonora com as respostas de seus pais para um questionário que investigou a ocorrência de episódios de otite média (OM) e os sintomas indicativos de desordens audiológicas e do processamento auditivo. MÉTODOS: após aplicação e análise das respostas do questionário, dois grupos foram formados: GO, com histórico de OM, e GC, sem este histórico. Cada grupo com 20 pré-escolares de ambos os gêneros foi submetido ao teste de localização da fonte sonora em cinco direções (Pereira, 1993). RESULTADOS: a comparação entre GO e GC não mostrou diferença estatisticamente significante (p=1,0000). CONCLUSÃO: as otites recorrentes na primeira infância não influenciaram no desempenho da habilidade de localização sonora dos pré-escolares deste estudo. Embora sejam dois instrumentos baratos e de fácil aplicação, o questionário e o teste de localização não foram suficientes para diferenciar os dois grupos testados.

PURPOSE: to compare the sound localization ability of 40 preschool children with their parents' answers. The questionnaire answered by the parents investigated otitis media (OM) episodes and symptoms that indicated the audiological and auditory processing disabilities. METHODS: after applying and analyzing the questionnaire's answers, two groups were formed: OG (with OM) and CG (control group). Each group with 20 preschool children, of both genders, was submitted to the sound localization test in five directions (according to Pereira, 1993). RESULTS: comparison between OG and CG did not reveal statistically significant difference (p=1.0000). CONCLUSION: OM episodes during first infancy did not influence the sound localization ability in this preschool children study. Although both used evaluation instruments (questionnaire and sound localization test) are cheap and easy to apply they are not sufficient to differ both tested groups.

Localização sonora em usuários de aparelhos de amplificação sonora individual / Sound localization by hearing aid users

OBJETIVO: comparar o desempenho, no teste de localização de fontes sonoras, de usuários de aparelhos de amplificação sonora individual (AASI) do tipo retroauricular e intracanal, com o desempenho de ouvintes normais, nos planos espaciais horizontal e sagital mediano, para as frequências de 500, 2.000 e 4.500 Hz; e correlacionar os acertos no teste de localização sonora com o tempo de uso dos AASI. MÉTODOS: foram testados oito ouvintes normais e 20 usuários de próteses auditivas, subdivididos em dois grupos. Um formado por 10 indivíduos usuários de próteses auditivas do tipo intracanal e o outro grupo formado por 10 usuários de próteses auditivas do tipo retroauricular. Todos foram submetidos ao teste de localização de fontes sonoras, no qual foram apresentados, aleatoriamente, três tipos de ondas quadradas, com frequências fundamentais em 0,5 kHz, 2 kHz e 4,5 kHz, na intensidade de 70 dBA. RESULTADOS: encontrou-se percentuais de acertos médios de 78,4 por cento, 72,2 por cento e 72,9 por cento para os ouvintes normais, em 0,5 kHz, 2 kHz e 4,5 kHz, respectivamente e 40,1 por cento, 39,4 por cento e 41,7 por cento para os usuários de aparelho de amplificação sonora individual. Quanto aos tipos de aparelhos, os usuários do modelo intracanal acertaram a origem da fonte sonora em 47,2 por cento das vezes e os usuários do modelo retroauricular em 37,4 por cento das vezes. Não foi observada correlação entre o percentual de acertos no teste de localização sonora e o tempo de uso da prótese auditiva. CONCLUSÃO: ouvintes normais localizam as fontes sonoras de maneira mais eficiente que os usuários de aparelho de amplificação sonora individual e, dentre estes, os que utilizam o modelo intracanal obtiveram melhor desempenho. Além disso, o tempo de uso não interferiu no desempenho para localizar a origem das fontes sonoras.

PURPOSE: to compare the sound localization performance of hearing aids users, with the performance of normal hearing in the horizontal and sagittal planes, at 0.5, 2 and 4.5 Hz; to correlate the correct responses in sound localization tasks and the use time of hearing aids. METHODS: eight normal hearing subjects and 20 hearing aid users were tested, subdivided into groups of 10 in-the-canal (ITC) hearing aid users and 10 behind-the-ear (BTE) hearing aid users. All subjects were tested with a sound localization device which had three types of square waves with fundamental frequencies at 0.5 kHz, 2 kHz and 4.5 kHz, at 70 dBA. RESULTS: the rate of correct responses in sound localization tasks was 78.4 percent, 72.2 percent and 72.9 percent for normal hearing subjects, at 0.5 kHz, 2 kHz and 4.5 kHz, respectively, and 40.1 percent, 39.4 percent, and 41.7 percent for hearing aid users. As for the types of hearing aids, users of ITC type hit the correctly sound localization in 47.2 percent and user of BTE type in 37.4 percent. CONCLUSION: normal hearing subjects locate sound sources more efficiently than hearing aid users, and among these, those using the ITC type obtained better performance. Moreover, the time of use does not interfere with the performance for locating the sound sources.

Habilidade de localização e lateralização sonora em deficientes visuais / Sound localization and lateralization in individuals with visual deficiency

OBJETIVO: Verificar o desempenho de ouvintes, cegos ou com visão subnormal, nos testes de localização sonora em cinco direções e de lateralização, comparando-o com indivíduos videntes, com sensibilidade auditiva normal, nas mesmas tarefas. MÉTODOS: Foram selecionados 21 indivíduos com sensibilidade auditiva normal, faixa etária média de 30 anos, de ambos os gêneros, reunidos pela presença cegueira e/ou visão subnormal congênita ou adquirida. Foram realizados os testes que compõem a avaliação audiológica básica, o Teste de Localização Sonora e o Teste de Lateralização com Som Verbal, nas técnicas ascendente e descendente. Os resultados obtidos com os testes realizados pelo grupo de 21 indivíduos com deficiência visual foram comparados com os de 40 adultos videntes e ouvintes normais. RESULTADOS: No grupo estudo (deficientes visuais), tanto na técnica ascendente quanto na descendente, existem diferenças estatisticamente significantes entre os limiares de lateralização sonora para as orelhas direita e esquerda. O maior limiar de lateralização foi observado na orelha esquerda em cada grupo. Em cada técnica, ascendente e descendente, não existiram diferenças estatisticamente significantes para o limiar de lateralização por orelha, em cada grupo. Comparando os dados do teste de lateralização sonora do grupo de deficientes visuais por técnica e orelha, com os dados do grupo de comparação de videntes, verificamos que existiram diferenças estatisticamente significantes em ambas as técnicas e orelhas, com exceção da orelha esquerda, na técnica ascendente. CONCLUSÃO: Os deficientes visuais avaliados têm um excelente desempenho em lateralização de sons, muito melhor do que sujeitos videntes e ouvintes típicos ou normais.

PURPOSE: To verify the auditory performance of blind or subnormal sight individuals in tests for sound localization in five directions and lateralization, compared to individuals with normal sight and normal auditory sensibility. METHODS: Twenty-one individuals with normal auditory sensibility were selected, mean age of 30 years, both genders, grouped according to presence of blindness and/or acquired or congenital subnormal sight. Audiological evaluation tests, Sound Localization Test and Lateralization Test with verbal sound, using both ascending and descending techniques, were carried out. Results obtained on the tests by the 21 subjects with visual deficiency were compared to those of 40 adults with normal sight and hearing. RESULTS: The visually impaired group, both in ascending and descending techniques, presented statistically significant differences between sound lateralization limits for right and left ears. The higher lateralization threshold was observed on the left ear in each group. In each technique, ascending and descending, there were no statistically significant differences in the lateralization threshold per ear in each group. Comparing data from the sound lateralization test of the visually impaired per technique and ear, with data from the comparison group with normal sight, it was verified that there were statistically significant differences for both techniques and ears, except for the left ear in the ascending technique. CONCLUSION: The visually impaired evaluated showed an excellent performance in sound lateralization, much better than individuals with normal sight and hearing.

A importância das variações espectrais transferidas anatomicamente para a localização de fontes sonoras / Head related transfer function relevance to sound source localization

OBJETIVOS: investigar a importância das dimensões anatômicas dos ombros e da cabeça para a localização de fontes sonoras por ouvintes normais, em ambiente reverberante; correlacionar o percentual de acertos na localização sonora com o comprimento e largura da cabeça e o comprimento e largura do ombro e observar a diferença entre as diversas freqüências sonoras apresentadas. MÉTODOS: a amostra foi composta por 52 indivíduos, 20 homens e 32 mulheres, os quais foram submetidos aos testes de otoscopia, audiometria tonal liminar, imitanciometria e emissões otoacústicas. Todos apresentaram audição dentro dos padrões de normalidade. Foram realizadas as medidas de comprimento e largura da cabeça e ombros. Posteriormente, os indivíduos foram submetidos ao teste de localização sonora, nos planos horizontal e vertical, nas freqüências de 500, 2.000 e 4.000 Hz. RESULTADOS: obteve-se correlação significativa (p <0,05) apenas entre a largura dos ombros e os acertos no plano horizontal utilizando-se as freqüências de 2 e 4 kHz. CONCLUSÃO: o percentual de acertos na localização sonora aumenta com o aumento do comprimento dos ombros nas freqüências de 2 e 4 kHz, no plano horizontal.

PURPOSE: to investigate the relevance of the head transfer function related to the sound localization by human normal hearing, in reverberant environment; to correlate the percentage of success in sound localization and the length and the width of the head and the shoulders, observing the difference among frequencies and the spatial planes. METHODS: the sample was made up by 52 individuals, 20 men and 2 women, which had been submitted to otoscopy, tonal audiometry and OAE. The measures related to length and width of the head and shoulders had been carried out too. Later, the individuals had been submitted to sound localization test, in the horizontal and vertical planes, and with the frequencies of 0.5, 2 and 4 kHz. Results: significant correlation was obtained (p<0.05) just between the width of the shoulders and the success in the horizontal plane, using 2 and 4 kHz. CONCLUSION: The percentage of success in the sound localization increases with the increase in the length of the shoulders using 2 and 4 kHz, in the horizontal plane.

Manufacture of a sound localization apparatus and its primary application / 中国耳鼻咽喉头颈外科

0.05). CONCLUSION The sound localization apparatus can test the localization ability of person, and it can be used in simply and reasonably.

Localization of the human primary auditory cortex by magnetic source imaging / 中华放射学杂志

0.05). Conclusions The primary auditory cortex could be precisely localized by MSI.

Sound Localization in Subjects with a Unilateral Hearing Loss according to Hearing Loss / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Sound localization in subjects with normal hearing is done by recognition of interaural difference of time, intensity and phase of sound source. Individuals with unilateral hearing losses, deprived of the binaural cues, are expected to have difficulty in localizing sound. The purpose of the research is to investigate the sound localizing ability in subjects with unilateral hearing losses to localize sound in horizontal plane by comparing with normal control group, and to know the effects of age, gender, stimulus type and hearing level. MATERIALS: Two groups of subjects participated in this study. The first group consisted of 60 normal hearing adults, in each age groups of 10 subjects, ranging from teens to sixties. The second group consisted of 50 subjects with unilateral hearing losses. METHODS: Sound localization ability was assessed by means of an array of eight loudspeakers positioned at the azimuth of 45 degrees each in the horizontal plane at a distance of 100 cm from the subject. The stimuli consisted of speech noise, narrow band noise centered at 500 Hz and 4000 Hz, pure tone of 500 Hz and 4000 Hz at the level of 45 dB HL for 5 seconds. RESULTS: 1) Speech noise was the most easily detected stimulus (p0.05). 3) The localization errors for speech noise increased significantly as hearing threshold increased in patients with unilateral hearing losses (p<0.001). CONCLUSION: The results suggest that speech noise is the most easily detected stimulus in directional discrimination test and that the ability of sound localization is degraded as hearing threshold is increased for patients with unilateral hearing losses.

Advantages of Frequency Specific Tri-microphone Binaural Wireless Hearing Aid Technology / 听力学及言语疾病杂志

Objective To examine adult speech recognition for words presented in different background noise when the adults used 4-band tri-microphone and traditional tri-microphone hearing aid technology,and to examine the ability of sound location when using wireless remote control.Methods A total 40(female 29,male 11) subjects with moderate to severe bilateral sensorineural hearing loss were encountered in this test,and were divided into two groups(group A and group B).With binaural fitting ACURIS P(frequency specific tri-microphone adaptive mode) and Triano 3 P(Tri-microphone adaptive mode),the patients were tested with speech recognition in two sound field through PB test and the accurateness of sound localization were investigated through questionnaire.Results Significant differences were found between the mean L50(the S/N at which 50% of running speech is correctly understood) obtained from group A versus group B in Tri-microphone adaptive directional condition in multiple sound fields(P