Application of International Speech Test Signal on Acceptable Noise Level Test in Mandarin Adults with Normal Hearing / 听力学及言语疾病杂志

Objective To study the use of the international speech test signal(ISTS) on acceptable noise level (ANL)test in Mandarin adults.Methods The Mandarin test materials and ISTS were used as test materials.The ANL test was performed on 40 normal hearing adults.For each case,the most comfortable loudness(MCL)and background noise level(BNL)were obtained.MCL minus BNL equal to ANL.Results The values of ANL under the Mandarin test materials and ISTS test materials were 39.31±6.97 and 41.85±7.60 dB HL,respectively.The values of BNL were 37.59±8.45 and 39.27±8.66 dB HL,respectively.The values of ANL were 1.53±5.61 and 2.45±5.58 dB,respectively in 40 normal hearing adults.There was no significant difference in the MCL,BNL and ANL between the test materials of Mandarin and ISTS (P＞ 0.05).Conclusion International speech test signal (ISTS) can be used on ANL test in Mandarin adults with normal hearing.

The Effects of Hearing Aid Digital Noise Reduction and Directionality on Acceptable Noise Level

OBJECTIVES: Two main digital signal processing technologies inside the modern hearing aid to provide the best conditions for hearing aid users are directionality (DIR) and digital noise reduction (DNR) algorithms. There are various possible settings for these algorithms. The present study evaluates the effects of various DIR and DNR conditions (both separately and in combination) on listening comfort among hearing aid users. METHODS: In 18 participants who received hearing aid fitting services from the Rehabilitation School of Shahid Beheshti University of Medical Sciences regularly, we applied acceptable noise level (ANL) as our subjective measure of listening comfort. We evaluated both of these under six different hearing aid conditions: omnidirectional-baseline, omnidirectional-broadband DNR, omnidirectional-multichannel DNR, directional, directional-broadband DNR, and directional-multichannel DNR. RESULTS: The ANL results ranged from −3 dB to 14 dB in all conditions. The results show, among all conditions, both the omnidirectional-baseline condition and the omnidirectional-broadband DNR condition are the worst conditions for listening in noise. The DIR always reduces the amount of noise that patients received during testing. The DNR algorithm does not improve listening in noise significantly when compared with the DIR algorithms. Although both DNR and DIR algorithms yielded a lower ANL, the DIR algorithm was more effective than the DNR. CONCLUSION: The DIR and DNR technologies provide listening comfort in the presence of noise. Thus, user benefit depends on how the digital signal processing settings inside the hearing aid are adjusted.

The Acceptable Noise Level Benefit From Directionality for Listeners With Severe Hearing Loss

OBJECTIVES: Directional microphone technology can enhance the speech intelligibility and listening comfort of listeners with hearing impairment. The main aim of this study is to investigate and compare the benefit derived by listeners with severe hearing loss from directional microphone technology with that derived by listeners with moderate hearing loss. METHODS: The acceptable noise levels (ANLs) of two groups of listeners with moderate or severe hearing impairment (17 subjects in each group) were measured under unaided, omnidirectional-baseline-aided, and directional-aided conditions. RESULTS: Although the absolute ANL of the listeners in the severe hearing loss group was significantly higher than that of the listeners in the moderate hearing loss group, their derived benefit was equivalent to that derived by the listeners in the moderate hearing loss group. ANL and hearing loss degree were significantly related. Specifically, the ANL increased with the severity of hearing loss. CONCLUSION: Directional microphone technology can provide the benefits of listening comfort to listeners with severe hearing loss.

Encoding of speech sounds at auditory brainstem level in good and poor hearing aid performers / Codificação dos sons da fala no nível do tronco encefálico auditivo em bons e maususuários de aparelhos auditivos

Abstract Introduction: Hearing aids are prescribed to alleviate loss of audibility. It has been reported that about 31% of hearing aid users reject their own hearing aid because of annoyance towards background noise. The reason for dissatisfaction can be located anywhere from the hearing aid microphone till the integrity of neurons along the auditory pathway. Objectives: To measure spectra from the output of hearing aid at the ear canal level and frequency following response recorded at the auditory brainstem from individuals with hearing impairment. Methods: A total of sixty participants having moderate sensorineural hearing impairment with age range from 15 to 65 years were involved. Each participant was classified as either Good or Poor Hearing aid Performers based on acceptable noise level measure. Stimuli /da/ and /si/ were presented through loudspeaker at 65 dB SPL. At the ear canal, the spectra were measured in the unaided and aided conditions. At auditory brainstem, frequency following response were recorded to the same stimuli from the participants. Results: Spectrum measured in each condition at ear canal was same in good hearing aid performers and poor hearing aid performers. At brainstem level, better F0 encoding; F0 and F1 energies were significantly higher in good hearing aid performers than in poor hearing aid performers. Though the hearing aid spectra were almost same between good hearing aid performers and poor hearing aid performers, subtle physiological variations exist at the auditory brainstem. Conclusion: The result of the present study suggests that neural encoding of speech sound at the brainstem level might be mediated distinctly in good hearing aid performers from that of poor hearing aid performers. Thus, it can be inferred that subtle physiological changes are evident at the auditory brainstem in a person who is willing to accept noise from those who are not willing to accept noise.

Resumo Introdução: Os aparelhos auditivos são prescritos para aliviar a perda de audibilidade. Tem sido relatado que 31% dos usuários rejeitam seu aparelho auditivo devido ao desconforto com o ruído de fundo. A razão para a insatisfação pode estar situada em qualquer local desde o microfone do aparelho auditivo até a integridade de neurônios ao longo da via auditiva. Objetivos: Medir espectros desde a saída do aparelho auditivo no nível do meato acústico externo e frequência de resposta (FFR) registrada no tronco encefálico de indivíduos com deficiência auditiva. Método: Foram selecionados 60 participantes com deficiência auditiva neurossensorial moderada, de 15 a 65 anos. Cada participante foi classificado como usuário bom ou mau de prótese auditiva (GHP ou PHP) com base na medida de nível de ruído aceitável (ANL). Estímulos/da/e/si/foram apresentados em alto-falante a 65 dB SPL. No meato acústico externo, os espectros foram medidos nas condições sem aparelho e com aparelho. No tronco encefálico auditivo, FFR foram registradas para os mesmos estímulos dos participantes. Resultados: Os espectros medidos em cada condição no meato acústico externo foram os mesmos em GHP e PHP. No nível do tronco cerebral, melhor codificação F0; energias de F0 e F1 foram significativamente maiores em GHP do que em PHP. Embora os espectros do aparelho auditivo fossem quase os mesmos entre GHP e PHP, existem variações fisiológicas sutis no tronco encefálico auditivo. Conclusão: O resultado do presente estudo sugere que a codificação neural do som da fala no nível do tronco encefálico pode ser mediada distintamente em GHP em comparação com PHP. Assim, pode-se inferir que mudanças fisiológicas sutis são evidentes no tronco encefálico em uma pessoa que está disposta a aceitar o ruído em comparação com aqueles que não estão dispostos a aceitar o ruído.

The Use of Acceptable Noise Level on Monaural and Binaural Amplification in Hearing Aids Fitting / 听力学及言语疾病杂志

Objective To compare the relationship of acceptable noise level (ANL) between monaural and binaural hearing aid in patients with bilateral moderate-to-severe hearing loss, and to investigate the clinical significance of the ANL in binaural hearing aid fitting and the predictive role in the hearing aid effect assessment.Methods A total of 15 patients with bilateral moderate-to-severe hearing loss were selected, and the most comfortable levels (MCL), background noise level (BNL) and calculate ANL were tested, respectively, in 4 conditions: without hearing aids, fitted only left ears, fitted only right ears and binaural fitting.Results The ANL in 15 subjects measured at 4 conditions were 18.87±5.26, 12.60±2.47, 12.00±2.90, and 5.13±1.25 dB S/N, respectively.The MCLs were 80.40±9.28, 63.73±5.15, 62.27±5.36, and 61.80±6.05 dB HL, respectively.The BNLs were 61.67±6.14, 51.13±3.94, 50.27±4.50, and 56.67±5.16 dB HL.The ANL difference between the only left and right fitting groups was not statistically significant(P>0.05).The ANL difference between the monaural or the binaural hearing aid group and without hearing aids group were statistically significant (P<0.05), respectively.Compared with the monaural hearing aid group, the binaural hearing aid group had significantly lower ANL(P<0.05).Conclusion For people with bilateral hearing loss, hearing aids can improve their ability to manage the background noise, and binaural hearing aid fitting is better than monaural.

Comparison of Acceptable Noise Levels Using Korean and Non-Semantic Speech Signals in Normal Hearing Subjects / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The acceptable noise level (ANL) test measures the maximum noise level that a subject can tolerate while following speech. Given the limited investigation of ANL across different languages, this study aimed to compare ANLs using both Korean semantic speech and non-semantic speech signals (reversed Korean speech and international speech test signal, ISTS) in normal-hearing subjects. SUBJECTS AND METHOD: Twenty-five subjects with normal hearing (9 males, 16 females, with the mean age of 28.5±3.15 years) were included in the study. ANLs were obtained using three speech materials (Korean speech, reversed Korean speech, and ISTS) as the target speech material and an eight-talker babble noise as the competing background noise. RESULTS: Generally, the inter-subject variability was large. The ANLs did not differ statistically regardless of the type of speech signal. CONCLUSION: The ANLs seemed to be unaffected by the meaningfulness or semantic contents of the target speech, at least in normal-hearing adults. Thus, non-meaningful speech signals or non-semantic material can be considered as the target signal for the implementation of ANL test.

Application of Music Testing Materials in Acceptable Noise Level Test / 听力学及言语疾病杂志

Objective To explore the feasibility of the application of music test materials in acceptable noise level (ANL) test.Methods We chose Mandarin proficiency test material,Mandarin music and accompaniment music to produce ANL test materials.The background noise was babble noise.A total of 40 normal hearing young people conduct ANL tests.Results The most comfortable loudness (MCL) obtained under the Mandarin short text test material,Mandarin music test material and accompaniment music test material were 39.10±7.43,43.85±9.53 and 44.10±10.83 dB,respectively.The maximum background noise level (BNL) were 37.91±8.65,44.52±11.23,43.65±12.89 dB HL,ANL values were 0.98±4.90,-0.90±3.78,0.45±4.65 dB S/N,respectively.The MCL and BNL values of Mandarin music test materials and accompaniment music test materials were higher than those of Mandarin short text test materials (P＜0.05),but there was no significant difference between MCL and BNL values in Mandarin music test materials and accompaniment music test materials (P ＞ 0.05).There was no significant difference in ANL among the three test materials (P＞0.05).Conclusion The music test material can be applied to the acceptable noise level test.The MCL value and the BNL value were higher under the music test material,which indicating that the acceptance of the music is higher in normal hearing people,whether or not the music test material containing lyrics has no effect on the ANL test results.

Measurement of Acceptable Noise Level with Background Music

BACKGROUND AND OBJECTIVES: Acceptable noise level (ANL) is a measure of the maximum background noise level (BNL) that a person is willing to tolerate while following a target story. Although researchers have used various sources of target sound in ANL measures, a limited type of background noise has been used. Extending the previous study of Gordon-Hickey & Moore (2007), the current study determined the effect of music genre and tempo on ANLs as possible factors affecting ANLs. We also investigated the relationships between individual ANLs and the familiarity of music samples and between music ANLs and subjective preference. SUBJECTS AND METHODS: Forty-one participants were seperated into two groups according to their ANLs, 29 low-ANL listeners and 12 high-ANL listeners. Using Korean ANL material, the individual ANLs were measured based on the listeners' most comfortable listening level and BNL. The ANLs were measured in six conditions, with different music tempo (fast, slow) and genre (K-pop, pop, classical) in a counterbalanced order. RESULTS: Overall, ANLs did not differ by the tempo of background music, but music genre significantly affected individual ANLs. We observed relatively higher ANLs with K-pop music and relatively lower ANLs with classical music. This tendency was similar in both low-ANL and high-ANL groups. However, the subjective ratings of music familiarity and preference affected ANLs differently for low-ANL and high-ANL groups. In contrast to the low-ANL listeners, the ANLs of the high-ANL listeners were significantly affected by music familiarity and preference. CONCLUSIONS: The genre of background music affected ANLs obtained using background music. The degree of music familiarity and preference appears to be associated with individual susceptibility to background music only for listeners who are greatly annoyed by background noise (high-ANL listeners).

Advantages of Binaural Amplification to Acceptable Noise Level of Directional Hearing Aid Users

OBJECTIVES: The goal of the present study was to examine whether Acceptable Noise Levels (ANLs) would be lower (greater acceptance of noise) in binaural listening than in monaural listening condition and also whether meaningfulness of background speech noise would affect ANLs for directional microphone hearing aid users. In addition, any relationships between the individual binaural benefits on ANLs and the individuals' demographic information were investigated. METHODS: Fourteen hearing aid users (mean age, 64 years) participated for experimental testing. For the ANL calculation, listeners' most comfortable listening levels and background noise level were measured. Using Korean ANL material, ANLs of all participants were evaluated under monaural and binaural amplification with a counterbalanced order. The ANLs were also compared across five types of competing speech noises, consisting of 1- through 8-talker background speech maskers. Seven young normal-hearing listeners (mean age, 27 years) participated for the same measurements as a pilot testing. RESULTS: The results demonstrated that directional hearing aid users accepted more noise (lower ANLs) with binaural amplification than with monaural amplification, regardless of the type of competing speech. When the background speech noise became more meaningful, hearing-impaired listeners accepted less amount of noise (higher ANLs), revealing that ANL is dependent on the intelligibility of the competing speech. The individuals' binaural advantages in ANLs were significantly greater for the listeners with longer experience of hearing aids, yet not related to their age or hearing thresholds. CONCLUSION: Binaural directional microphone processing allowed hearing aid users to accept a greater amount of background noise, which may in turn improve listeners' hearing aid success. Informational masking substantially influenced background noise acceptance. Given a significant association between ANLs and duration of hearing aid usage, ANL measurement can be useful for clinical counseling of binaural hearing aid candidates or unsuccessful users.

Effects of Mandarin Speech Rate on Mandarin AcceptabIe Noise LeveI Test in NormaI Hearing AduIts / 听力学及言语疾病杂志

Objective To investigate the effects of Mandarin speech rate on Mandarin acceptable noise level test in normal hearing adults.Methods Using the national Putonghua proficiency test material to produce 0.8 times,1.0 times and 1.2 times speed rate of ANL test materials.ANL tests were measured for 58 normal hearing a-dults using different peed matetrials.For each case,the most comfortable loudness(MCL)and background noise lev-el(BNL)were found.The ANL was then computed by subtracting the mean BNL from MCL.ResuIts Statistic anal-ysis indicated that there were no significant differences of the ANL(P>0.05)among the differenct speed materials, there were no correlation between MCL-ANL (P>0.05),negatively correlation between BNL-ANL(P<0.05)a-mong the differenct speed materials.ConcIusion Mandarin speech speed does not effect ANL test,the more the in-dividual’s ability to accept the background noise,the smaller the value of ANL.

A Study of Clinical Feasibility of Acceptable Noise Level Test / 听力学及言语疾病杂志

Objective To observe the clinical feasibility of the acceptable noise level (ANL) test ,analyze the effect of different test instructions to the result of Mandarin acceptable noise level test .Methods Twelve young peo-ple (24 ears) with normal pure-tone test and acoustic immittance test (threshold≤15 dB HL) were included in this study .They were randomly divided into two groups with 12 ears in each group .Group A received the same test in-struction firstly and then received different instructions depended on the different translation of English instruction by tester .Group B received the reverse test order .The acceptable noise level(ANL) ,most comfortable level(MCL) and back groud noise level(BNL) were analyzed .Results The average value of ANL was 7 .5 ± 6 .61 and 8 .29 ± 6 .54 dB SPL ;the average value of most comfortable level (MCL) was 83 .58 ± 8 .57 and 85 .41 ± 8 .89 dB SPL ;the average value of background noise level (BNL) were 78 .92 ± 10 .56 and 77 .13 ± 7 .91 dB SPL respectivoly .The difference of MCL ,BNL ,ANL in these two groups were not statistically significant (P>0 .05) .Test method 1 re-sulted in great individual differences in ANL ,which it ranged from -6 .4 to 20 .12 dB S/N .While ANL from test method 2 ranged from 2 .50~20 .12 dB S/N .Conclusion Different test instruction do not correlated to the results of acceptable noise level ,testers can translate the English instruction by different ways so that it is convenient to the application and clinical research of ANL test .