压耳式及插入式耳机给声诱发听性脑干反应

目的比较以压耳式及插入式耳机给声诱发的听性脑干反应(ABR)的差异。方法以TDH-39P压耳式和ER-3A插入式耳机给声,通过真耳测试短声在外耳道的频谱图,对一组听力正常青年人(男30耳,女24耳)进行短声诱发ABR测试,并观察对侧给予白噪声掩蔽后ABR反应阈的改变。结果两种给声方式诱发出极为相似的ABR波形,两者反应阈及潜伏期均无显著性差异(P>0.05)。采用插入式耳机对侧加40～70dBSPL强度的白噪声对ABR的阈值及阈上10dB强度下波V潜伏期均无显著性影响(P>0.05)。真耳分析测试结果显示两种耳机给声方式下外耳道短声的频谱图极为相似,仅强度相差3dB(0.5～4kHz)。结论插入式和压耳式耳机给声方式的ABR测试结果之间无显著性差异。为此,建议临床中应准备两种给声方式并获取相应的正常值,以便使用时灵活选择。插入式耳机对侧给声的ABR掩蔽不存在中枢掩蔽现象。     

插入式耳机在纯音听阈测试中的应用

目的　探讨标准插入式耳机的耳间衰减值。方法　将 75名年龄 12～ 6 8岁的一耳听力正常 ,另一耳重度到极重度感音神经性聋的受试者 (男 4 7名 ,女 2 8名 ) ,随机分为两组 ,分别以TDH - 39压耳式耳机 (n =4 6 )和ER - 3A标准插入式耳机 (n =2 9)进行耳间衰减值的测量及比较。结果　①ER - 3A插入式耳机的耳间衰减最大值为 10 5dB ,最小值为 5 5dB ,TDH - 39压耳式耳机的耳间衰减最大值为 90dB ,最小值为 4 5dB ;②对不同耳机组 ,不同频率的耳间衰减值进行双因素方差分析 (耳机×频率 ) ,两种耳机的耳间衰减的差异具有显著性 (F =6 8.5 2 6 ,P =0 .0 0 0 ) ,各个频率耳间衰减的差异也具有显著性 (F =10 .4 16 ,P =0 .0 0 0 ) ;③在插入式耳机组中 ,不同频率的耳间衰减值经单因素方差分析 ,其差异有显著性意义 (F =11.6 30 ,P =0 .0 0 )。结论　插入式耳机因为增大了耳间衰减 ,从而减少了交叉听力及超掩蔽的可能 ,在一定程度上可以解决传统的压耳式耳机难以解决的掩蔽问题     

头戴式气导耳机评估完全耳道式助听器助听听阈的可行性研究

目的：验证使用头戴式气导耳机对完全耳道式（completey-in-the-canal,CIC）助听器配戴者进行助听听阈评估是否具有可行性。方法对26例（35耳）CIC型助听器配戴者分别进行裸耳纯音听阈测试、声场条件下的助听听阈测试和头戴式气导耳机条件下的助听听阈测试，并对结果进行统计学分析。结果 CIC型助听器配戴者声场条件下与头戴式气导耳机条件下的助听听阈在250、1000、2000和4000 Hz处差异有统计学意义（P<0.05），但差值均＜5 dB HL；声场条件下的助听听阈、头戴式气导耳机条件下的助听听阈和裸耳听阈两两间在250、500、1000、2000和4000 Hz频率下均呈显著直线相关趋势（P<0.01）。结论CIC助听器配戴者可用头戴式气导耳机进行助听听阈测试，但由于本研究只观察了250～4000 Hz的助听听阈，因此使用头戴式气导耳机进行评估的方法并不能替代声场评估，还需要进一步研究。     

地铁车厢内噪声对不同类型耳机佩带舒适音量的影响

目的 探讨地铁车厢内噪声对不同类型耳机佩戴者使用音量的影响.方法 以75例听力正常受试者为研究对象,每例对象分别佩戴入耳式、耳塞式、贴耳式和耳罩式耳机,在安静环境和北京地铁7号线车厢背景噪声(LAeq,1s均值为80.3 dB A)下听同一首音乐,选择舒适的音量档位,分析背景噪声、耳机类型对受试者耳机使用音量的影响.结果 在地铁车厢噪声环境下,受试者使用入耳式、耳塞式、贴耳式和耳罩式耳机选择舒适音量时人耳处噪声值分别为76.6±4.7、84.3±5.0、82.3±4.2、80.8±4.2 dB A,安静环境下分别为65.5±6.8、71.9±7.1、69.5±7.5、67.9±7.3 dB A;从安静环境到地铁车厢噪声环境,受试者的舒适音量平均提高了10 dB A以上.根据WHO噪声性聋的限值计算得到,不佩戴耳机每天暴露在上述地铁车厢背景噪声下不超过134 mins,使用上述耳机时时长分别不超过315、54、85、120 mins,可以避免噪声性听力损伤的发生.结论 地铁车厢噪声和耳机类型对耳机使用者舒适音量的影响较大;在地铁车厢嘈杂环境中,使用隔声性能较好的入耳式耳机,尽管调高了耳机舒适音量,人耳处实际噪声暴露水平仍可能低于不使用耳机时车厢噪声水平.     

ER－3A插入式耳机的基准等效阈声压级测试

插入式耳机，具有隔噪声性能好并能改善贴耳式耳机带来的堵耳效应和耳间效应等不良影响，可作为一种新型的标准耳机在临床测听中应用。为确定对国际标准“插入式耳机纯音基准等效阈声压级”的等效采用程度制订我国相应的国家标准，对３０名耳科正常人采用ＥＲ－３Ａ插入式耳机的等效阈声压级进行了测试，并与制订ＩＳＯ３８９－２所依据的几个主要研究结果相比较，数据基本一致。表明ＩＳＯ３８９－２（１９９４Ｅ）所规定的标准对我国是适用的，可以等效采用ＩＳＯ３８９－２制订我国的国家标准。     

自动听力计罩耳式耳机堵耳效应研究

目的测定罩耳式耳机在自动听力计骨导听阈检测过程中的低频区堵耳效应。方法招募健听青年志愿者,采用心理声学方法,检测SFTest 330型听力计在手动、自动两种模式下骨导振子安置于前额时测试耳在250、500、1000、2000及4000 Hz处堵耳效应,并与临床诊断听力计检测结果相比较。结果共21名(42耳)受试者入组,随着测试频率增高,堵耳效应逐渐减小;至4000 Hz处,3种情况下的堵耳效应降低至1.00±4.27~4.38±6.52;自动模式下于250 Hz处堵耳效应达8.75±6.96 dB,但小于AC40诊断型听力计于250 Hz处堵耳效应值(14.00±6.32),其SFTest 330型听力计手动、自动模式下堵耳效应无统计学差异(P>0.05)。结论SFTest 330型听力计自动测听模式下低频堵耳效应明显,进一步行更大内腔容积的罩耳式耳机测试有望降低该种情况下的堵耳效应。     

纯音听力计与自描(Békésy)听力计测定的听阈对比

听阈测定中,工具的不同是阈值变化的主要原因之一。目前,通用的测听工具是纯音听力计和自描听力计。作者从115例、年龄为25～63岁的男性船厂工人的听闹测定中,进行了这二种听力计的阈值对比。采用的纯音听力计的Madsen OB 60,耳机为配有MX-41/AR外垫的TDH-39M型。自描听力计为Demlar 120型,耳机为配有上述外垫的TDH-49 P型。二种听力计分别按ISOR 389(1964)和ANSI S 3.6(1969)标准校定,但经同一仿真耳校正,其精确度与稳定性均优于±1分贝。衰减范围:纯音听力计从+10分贝起以5分     

三种护耳器降噪功能声学特点的对比研究

目的 通过对护耳器的降噪功能声学特性的检测，了解国内护耳器的降噪功能是否达到了其出厂标准和国家标准，并与国外的护耳器进行比较。方法 正常听力的人群，采用l／3倍频程窄带噪声，中心频率为0．125～8kHz，真耳听阈衰减法(real—ear attenuation at threshold，REAT)的声场测试方法得到三种护耳器(国内两种，国外一种)的声衰减值，采用方差分析比较其差别。并与标准比较。结果 国内与国外耳罩声衰减值从0．125到8kHz都有显著性差异，国内耳罩与国家标准相比较，上海XZK型耳罩只在2、8 kHz符合其标准，长沙生产的耳罩在0．5、2、8kHz达到了标准。其余的频率均未达到国家的标准和出厂的标准。E—A—R model 1000与其出厂的标准相比较在6．3、8kHz未达到其出厂的标准。采用国内的标准，E—A—R model 1000其声衰减值均达到了我国国家标准。结论 国内的耳罩其声衰减值与国外的相比较有显著性差异，同时分别与国内和国外的标准相比较，国内产品符合标准的频率较少，而E—A—R modal 1000未符合其标准的频率则较少。     

扬声器和耳机条件下汉语普通话噪声中听力测试的比较研究

目的比较在扬声器和耳机两种不同给声方式下使用汉语普通话版的噪声下听力测试（HINT，Hearing in Noise Test）材料进行言语识别阈测试的差异。方法使用BLIMP测试软件对10名正常听力受试者（年龄23-27岁）进行MHINT的测试。10名受试者随机分成两组，每组分别采用扬声器和耳机作为给声方式。对两种给声方式下所得噪声下言语识别阈值进行秩和检验。结果在分别以字（character，P=0．421）和词（word，P=0．841）作为评分单位的测试中，以声场扬声器及耳机作为给声方式，差异均没有显著性。结论可以使用耳机代替声场扬声器进行汉语普通话HINT测试。信号校准对言语测听的可信度和可比性非常重要。     

慢性化脓性中耳炎完壁术式与开放术式研究

目的:对慢性化脓性中耳炎完壁术式及开放术式的适应证、患者术后生活质量进行研究,为术式的选择提供参考。方法:对慢性化脓性中耳炎行完壁术式或开放术式患者的临床资料进行分析总结。采用纯音测听、声导抗术腔容积测定、耳内镜及慢性耳病调查量表(中文版)对患者进行追踪随访。结果:①术后干耳率完壁术式与开放术式分别为98.7%、98.6%(P>0.05);②干耳时间完壁术式为(40.1±21.2)d,开放术式为(53.5±15.0)d(P<0.05);③患侧耳道容积/对侧正常耳耳道容积完壁术式为1.16±0.10,开放术式为2.05±1.19(P<0.05);④慢性耳病调查量表得分完壁术式为(91.2±6.8)分,开放术式为(72.0±7.7)分(P<0.05);⑤术后认为耳道口扩大、影响外观者的比例,完壁术式为5.7%,开放术式为80.8%(P<0.05);⑥术后主观听力改善者完壁术式占58.9%,开放术式占24.2%(P<0.05);但纯音测听显示听阈及骨气导差2组差异无统计学意义(P>0.05);⑦术后满意度得分完壁术式、开放术式分别为9.55分和8.11分(P<0.05)。结论:①行完壁术式的患者耳道形态接近正常,干耳时间缩短,生活质量较开放术式有明显提高。②对于富有经验的耳科医生,完壁术式的适应证可以扩展至硬化型及板障型乳突、部分伴有解剖变异及有颅内外并发症的患者。     

A comparison of inter-aural attenuation with the Etymotic ER-3A insert earphone and the Telephonics TDH-39 supra-aural earphone.

One of the many reported advantages of the insert earphone over the supra-aural earphone is increased inter-aural attenuation (IA). Minimum values of IA determine the need for masking of the non-test ear in air-conduction audiometry. The aim of the present study was to measure inter-aural attenuation for the Etymotic Research ER-3A insert earphone (with deep and shallow insertion of the ear plug within the ear canal) and compare this with the supra-aural Telephonics TDH-39/MX41-AR earphone/cushion combination. Subjects were 18 adults ranging in age from 38 to 68 years (mean 50 years). Each subject had no hearing in one ear following translabyrinthine surgery for removal of an acoustic neuroma. The opposite ear had hearing thresholds better than 40 dB HL and an air-bone gap of less than 10 dB at any audiometric frequency. Pure tone air-conduction thresholds were obtained in the range 0.25-8 kHz. Deep insertion of the insert earphone was deemed to occur when the outside edge of the ear plug was flush with the entrance of the ear canal. Shallow insertion was deemed to occur when half of the ear plug (6 mm) was inside the entrance of the ear canal. IA was defined operationally as the difference between the good-ear and poor-ear not-masked air conduction threshold for a given audiometric frequency and earphone. The results show that the TDH-39/MX41-AR combination provides a median IA of approximately 60 dB with a lower limit of approximately 45 dB. Greater IA was obtained with the ER-3A insert earphone but this depended on the depth of insertion. With a deep insertion, the 1A values were some 15-20 dB greater than with the supra-aural earphone. Although frequency-specific IA values are provided, a simple rule of thumb is to apply masking to the non-test ear when the pure tone airconduction signal from the ER-3A insert earphone exceeds the bone conduction threshold of the non-test ear by 55 dB HL or more. If it is not possible to obtain a deep insertion depth this value should be reduced by 5 dB.     

Interaural attenuation for tubephone insert earphones

Interaural attenuation of pure tone and speech signals was evaluated for a new audiometric insert earphone, the ER-3A tubephone, and a conventional TDH-49P supra-aural earphone in seven unilaterally deaf adult subjects. These results validate and extend the interaural attenuation data reported by the manufacturer of the ER-3A and his associates. At frequencies of 0.5 to 1 kHz, mean interaural attenuation for the deeply inserted ER-3A decreased from 94+ dB to 81 dB, with the lowest value for any subject, 75 dB. Interaural attenuation for speech approximated that of the 1 to 2 kHz frequency range. The ER-3A tubephone provides significantly greater acoustic isolation between the two ears in the low-mid frequency audiometric range than the conventional supra-aural earphone.     

Attenuation values for a supra-aural earphone for children and insert earphone for children and adults.

Earphone attenuation values were determined for 17 children (6-14 years old) using supra-aural (TDH-49P/Model 51 cushion) and insert earphones (E-A-Rtone 3A) terminated by an E-A-Rlink 3A (for normal size ear canals) or E-A-Rlink 3B (for small size ear canals) foam eartips, and for 10 adults having small ear canals using insert earphones and E-A-Rlink 3B foam eartips. The test signals were 1/3-octave bands of noise presented in a diffuse sound field (re: ANSI S12.6-1984). The supra-aural earphone attenuation values for the children were slightly higher (more attenuation) or similar to reported adult values, and always lower (less attenuation) compared with insert earphone/E-A-Rlink 3A (IE/3A) or 3B (IE/3B) values for both children and adults. The IE/3B attenuation values were similar between the children and adults and provided slightly more attenuation than the IE/3A. Overall, the results indicated that the ANSI S3.1-1991 maximum permissible ambient noise levels allowed in a test room for ears covered testing with a supra-aural earphone, which were determined using adult values, are appropriate for testing children. Future revisions of ANSI S3.1-1991 may include maximum permissible ambient noise levels for testing with insert earphones. The IE/3A and IE/3B attenuation values could be used for that purpose. In the meantime, because more attenuation was provided by the IE/3A and IE/3B, they can be used for testing both children and adults in higher ambient noise levels than specified in ANSI S3.1-1991.     

Three studies comparing performance of the ER-3A tubephone with the TDH-50P earphone

Three studies compared the performance of the ER-3A Tubephone insert earphone and the TDH-50P-MX41/AR supra-aural earphone. The three factors addressed were: threshold differences in children 7 to 10 yr old compared to adults, differences in real ear attenuation, and threshold differences in the presence of high background noise levels. The influence of insertion depth of the ER-3A Tubephone was also investigated. Findings showed no significant threshold differences between children and adults, significantly better real ear attenuation for the ER-3A Tubephone, and significantly better thresholds for the ER-3A in the presence of high background noise levels. Most critically, there was a significant change in attenuation characteristics of the ER-3A Tubephone, which was dependent on the insertion depth of the ear-tip.     

How does the sound pressure generated by circumaural, supra-aural, and insert earphones differ for adult and infant ears?

OBJECTIVE: To determine how the ear canal sound pressure levels generated by circumaural, supra-aural, and insert earphones differ when coupled to the normal adult and infant ear. DESIGN: The ratio between the sound pressure generated in an adult ear and an infant ear was calculated for three types of earphones: a circumaural earphone (Natus Medical, ALGO with Flexicoupler), a supra-aural earphone (Telephonics, TDH-49 with MXAR cushion), and an insert earphone placed in the ear canal (Etymoup and down arrow tic Research, ER-3A). The calculations are based on (1) previously published measurements of ear canal impedances in adult and infant (ages 1, 3, 6, 12, and 24 months) ears (Keefe et al., 1993, Acoustic Society of America, 94:2617-2638), (2) measurements of the Thévenin equivalent for each earphone configuration, and (3) acoustic models of the ear canal and external ear. RESULTS: Sound-pressure levels depend on the ear canal location at which they are measured. For pressures at the earphone: (1) Circumaural and supra-aural earphones produce changes between infant and adult ears that are less than 3 dB at all frequencies, and (2) insert earphones produce infant pressures that are up to 15 dB greater than adult pressures. For pressures at the tympanic membrane: (1) Circumaural and supra-aural earphones produce infant pressures that are within 2 dB of adult ears at frequencies below 2000 Hz and that are 5 to 7 dB smaller in infant ears than adult ears above 2000 Hz, and (2) insert earphones produce pressures that are 5 to 8 dB larger in infant ears than adult ears across all audiometric frequencies. CONCLUSIONS: Sound pressures generated by all earphone types (circumaural, supra-aural, and insert) depend on the dimensions of the ear canal and on the impedance of the ear at the tympanic membrane (e.g., infant versus adult). Specific conclusions depend on the location along the ear canal at which the changes between adult and infant ears are referenced (i.e., the earphone output location or the tympanic membrane). With circumaural and supra-aural earphones, the relatively large volume of air within the cuff of the earphone dominates the acoustic load that these earphones must drive, and differences in sound pressure generated in infant and adult ears are generally smaller than those with the insert earphone in which the changes in ear canal dimensions and impedance at the tympanic membrane have a bigger effect on the load the earphone must drive.     

A comparison of the variability in thresholds measured with insert and conventional supra-aural earphones

The purpose of this study was to evaluate the reliability and comparability of the commercially available insert earphone Etymotic Research ER-3A and the commonly available supra-aural TDH earphone. Thirteen subjects were tested five times with the ER-3A and five times with TDH-49P with MX-41/AR cushions. Threshold determinations were obtained utilizing a sweep-frequency audiometer in the range 0.25-8 kHz. The results showed that the reliability of the ER-3A earphone as measured by intra-individual variation, was comparable to that obtained with the TDH earphone. No evidence was found indicating an increased variability due to the positioning of the insert earphone's coupling device in the ear canal. Comparison of thresholds obtained with both devices indicated that the manufacturer's suggested correction values were appropriate.     

Efficacy of earphones for 12- to 24-month-old children during visual reinforcement audiometry

Objective: Efficacy of insert and supra-aural earphones during visual reinforcement audiometry (VRA) was investigated for 12- to 24-month-old children. Design: VRA testing began in the soundfield and transitioned to either insert or supra-aural earphones. Audiologists recorded threshold estimates, participant behaviors, and an overall subjective rating of earphone acceptance. Study sample: One hundred and eighty-six 12- to 24-month-old children referred to the Department of Audiology at St. Louis Children’s Hospital for a variety of reasons. Results: Subjective ratings indicated high acceptance of insert earphones (84%) and supra-aural earphones (80%) despite negative behaviors. There was no significant difference in the number of threshold estimates based on earphone type for 12- to 17-month-old participants. Participants in the 18- to 24-month-old age group provided significantly more threshold estimates with insert earphones (mean?=?5.3 threshold estimates, SD?=?3.5) than with supra-aural earphones (mean?=?2.9 threshold estimates, SD?=?2.9). All seven participants who rejected earphone placement were successfully reconditioned for soundfield testing. Conclusions: Data support the use of insert earphones during VRA, especially with 18-to 24-month-old children, to obtain ear-specific information.     

Test-retest variability in audiometric threshold with supraaural and insert earphones among children and adults

The effect of age and earphone condition on test-retest intrasubject variability in audiometric threshold was investigated. Ten subjects in each of the following age groups were investigated: 6-9 years, 10-13 years and young adults. Test-retest audiometric thresholds were collected at six frequencies (250, 500, 1,000, 2,000, 4,000 and 8,000 Hz) under three earphone conditions (Telephonics TDH-50P supraaural and Etymotic Research ER-3A insert earphone coupled to an immittance probe cuff or a foam insert). No statistically significant differences were found in variability of test-retest differences as a function of age, earphone condition or test frequency (p greater than 0.05). The clinical application of the insert earphone is recommended with children and adults as it affords no greater test-retest variability and at the same time provides a solution to a number of limitations incurred with the use of the supraaural earphone.     

Attenuation provided by four different audiometric earphone systems

The attenuation provided by TDH earphones in MX-41/AR and P/N 51 cushions, Audiocup earphone enclosures and ER-3A insert earphones with ER3-14 foam earplugs was determined for 30 normally hearing subjects using a real-ear attenuation at threshold paradigm. The MX-41/AR and P/N 51 cushions provided about the same amount of attenuation which was less than the attenuation provided by the Audiocup enclosures. The ER-3A/ER3-14 provided the highest amount of attenuation. The MX-41/AR and ER-3A/ER3-14 attenuation values were in agreement with other studies using similar methodology. However, the attenuation provided by the Audiocup enclosures was considerably less, in the lower frequencies, than reported in two other studies. ANSI S3.1-1977 supra-aural earphone cushion attenuation values, which were determined using pure-tones presented in a free-field, should be replaced by earphone cushion attenuation values determined with 1/3 octave bands of noise presented in a diffuse sound field.     

Middle ear pathology can affect the ear-canal sound pressure generated by audiologic earphones

OBJECTIVE: To determine how the ear-canal sound pressures generated by earphones differ between normal and pathologic middle ears. DESIGN: Measurements of ear-canal sound pressures generated by the Etymtic Research ER-3A insert earphone in normal ears (N = 12) were compared with the pressures generated in abnormal ears with mastoidectomy bowls (N = 15), tympanostomy tubes (N = 5), and tympanic-membrane perforations (N = 5). Similar measurements were made with the Telephonics TDH-49 supra-aural earphone in normal ears (N = 10) and abnormal ears with mastoidectomy bowls (N = 10), tympanostomy tubes (N = 4), and tympanic-membrane perforations (N = 5). RESULTS: With the insert earphone, the sound pressures generated in the mastoid-bowl ears were all smaller than the pressures generated in normal ears; from 250 to 1000 Hz the difference in pressure level was nearly frequency independent and ranged from -3 to -15 dB; from 1000 to 4000 Hz the reduction in level increased with frequency and ranged from -5 dB to -35 dB. In the ears with tympanostomy tubes and perforations the sound pressures were always smaller than in normal ears at frequencies below 1000 Hz; the largest differences occurred below 500 Hz and ranged from -5 to -25 dB. With the supra-aural earphone, the sound pressures in ears with the three pathologic conditions were more variable than those with the insert earphone. Generally, sound pressures in the ears with mastoid bowls were lower than those in normal ears for frequencies below about 500 Hz; above about 500 Hz the pressures showed sharp minima and maxima that were not seen in the normal ears. The ears with tympanostomy tubes and tympanic-membrane perforations also showed reduced ear-canal pressures at the lower frequencies, but at higher frequencies these ear-canal pressures were generally similar to the pressures measured in the normal ears. CONCLUSIONS: When the middle ear is not normal, ear-canal sound pressures can differ by up to 35 dB from the normal-ear value. Because the pressure level generally is decreased in the pathologic conditions that were studied, the measured hearing loss would exaggerate substantially the actual loss in ear sensitivity. The variations depend on the earphone, the middle ear pathology, and frequency. Uncontrolled variations in ear-canal pressure, whether caused by a poor earphone-to-ear connection or by abnormal middle ear impedance, could be corrected with audiometers that measure sound pressures during hearing tests.