Beattie R C
Department of Communicative Disorders, California State University, Long Beach 90840, USA.
Scand Audiol. 1998;27(2):120-6. doi: 10.1080/010503998420360.
Early auditory evoked response (ABR) audiometry is useful for estimating auditory sensitivity in infants and other difficult-to-test populations. Several investigations advocate using bone-conducted stimuli, in addition to air-conducted stimuli, for screening infants with hearing loss or for ascertaining the presence and magnitude of a conductive hearing loss. The present study was designed to gather normative Wave V latency-intensity data with an insert earphone (EARTONE 3A) and a bone vibrator (Radioear B-71). Forty normal-hearing subjects were tested with air-conducted and bone-conducted clicks at intensities of 55, 40, 30, 20, and 10 dB SL. The stimulus waveforms showed a click onset delay of 0.1 ms for the 3A insert earphone. It is important to note that our ABR latencies were not adjusted to account for these differences. The results revealed that both the air-conduction and bone-conduction functions exhibited Wave V latencies of 7.0 ms at 55 dB SL. Although both functions exhibited increased latencies as intensity decreased to 10 dB SL, the air-conducted clicks yielded somewhat longer latencies than the bone-conducted clicks. To allow direct comparison of the air-conduction and bone-conduction latency-intensity function, the bone-conduction function must be corrected by approximately +0.3 ms at 40 dB, +0.4 ms at 30 dB, +0.5 ms at 20 dB, and +0.8 ms 10 dB nHL. No correction is needed at 55 dB. The present study suggests that it may not be appropriate to apply a single correction value (e.g., 0.5 ms) to the entire latency-intensity function. If clinicians elect to use published latency-intensity data, they must employ procedure similar to those that were used to collect the normative data. Otherwise, individual clinics should generate normative latency-intensity data using well-defined procedures. An alternative to generating latency-intensity functions is to compare ABR air-conduction and bone-conduction thresholds. This procedure is advantageous because threshold responses are not as sensitive as latency measures to slight changes in instrumentation and procedures. The normative air-conduction and/or bone-conduction values presented in this investigation are offered as a baseline for either latency-intensity or threshold comparisons.
早期听觉诱发电位（ABR）听力测定法对于评估婴儿及其他难以测试的人群的听觉敏感度很有用。多项研究主张，除了气导刺激外，还应使用骨导刺激来筛查听力损失婴儿或确定传导性听力损失的存在及程度。本研究旨在收集使用插入式耳机（EARTONE 3A）和骨振动器（Radioear B - 71）时的标准V波潜伏期 - 强度数据。40名听力正常的受试者接受了强度为55、40、30、20和10 dB SL的气导和骨导短声测试。刺激波形显示，3A插入式耳机的短声起始延迟为0.1 ms。需要注意的是，我们的ABR潜伏期未针对这些差异进行调整。结果显示，在55 dB SL时，气导和骨导功能的V波潜伏期均为7.0 ms。尽管随着强度降至10 dB SL，两种功能的潜伏期均增加，但气导短声产生的潜伏期比骨导短声略长。为了直接比较气导和骨导潜伏期 - 强度函数，骨导功能必须在40 dB时校正约 +0.3 ms，30 dB时校正 +0.4 ms，20 dB时校正 +0.5 ms，10 dB nHL时校正 +0.8 ms。55 dB时无需校正。本研究表明，对整个潜伏期 - 强度函数应用单一校正值（例如0.5 ms）可能不合适。如果临床医生选择使用已发表的潜伏期 - 强度数据，他们必须采用与收集标准数据时类似的程序。否则，各个诊所应使用明确的程序生成标准潜伏期 - 强度数据。生成潜伏期 - 强度函数的另一种方法是比较ABR气导和骨导阈值。此程序具有优势，因为阈值反应对仪器和程序的微小变化不如潜伏期测量敏感。本研究中呈现的标准气导和/或骨导值可作为潜伏期 - 强度或阈值比较的基线。
