1HEARing Cooperative Research Centre, Carlton, Victoria, Australia; and 2National Acoustic Laboratories, Macquarie Park, New South Wales, Australia.
Ear Hear. 2014 Jan-Feb;35(1):e1-8. doi: 10.1097/AUD.0b013e31829e058f.
The primary objective of this study was to determine whether a combination of automatically administered pure-tone audiometry and a tone-in-noise detection task, both delivered via an air conduction (AC) pathway, could reliably and validly predict the presence of a conductive component to the hearing loss. The authors hypothesized that performance on the battery of tests would vary according to hearing loss type. A secondary objective was to evaluate the reliability and validity of a novel automatic audiometry algorithm to assess its suitability for inclusion in the test battery.
Participants underwent a series of hearing assessments that were conducted in a randomized order: manual pure-tone air conduction audiometry and bone conduction audiometry; automatic pure-tone air conduction audiometry; and an automatic tone-in-noise detection task. The automatic tests were each administered twice. The ability of the automatic test battery to: (a) predict the presence of an air-bone gap (ABG); and (b) accurately measure AC hearing thresholds was assessed against the results of manual audiometry. Test-retest conditions were compared to determine the reliability of each component of the automatic test battery. Data were collected on 120 ears from normal-hearing and conductive, sensorineural, and mixed hearing-loss subgroups.
Performance differences between different types of hearing loss were observed. Ears with a conductive component (conductive and mixed ears) tended to have normal signal to noise ratios (SNR) despite impaired thresholds in quiet, while ears without a conductive component (normal and sensorineural ears) demonstrated, on average, an increasing relationship between their thresholds in quiet and their achieved SNR. Using the relationship between these two measures among ears with no conductive component as a benchmark, the likelihood that an ear has a conductive component can be estimated based on the deviation from this benchmark. The sensitivity and specificity of the test battery vary depending on the size of this deviation, but increase with increasing ABG size, with decreasing test frequency, and when results from multiple test frequencies are taken into account. The individual automatic tests comprising the battery were found to be reliable and valid, with strong, significant correlations between the test and retest results (r = 0.81 to 0.99; p < 0.0001) and between automatic and manual audiometry procedures (r = 0.98 to 0.99; p < 0.0001).
The presence of an ABG can be predicted with a reasonably high degree of accuracy using AC tests alone. Applications of such a test battery include any clinical context in which bone conduction audiometry or specialized diagnostic equipment is unavailable or impractical. Examples of these include self-fitting hearing aids, whose efficacy relies on the ability of the device to automatically administer an in situ hearing test; self-administered adult hearing screenings in both clinical and home environments; large-scale industrial hearing conservation programs; and test environments in which ambient noise levels exceed the maximum permissible levels for unoccluded ears.
本研究的主要目的是确定通过空气传导（AC）通路自动进行纯音听力测试和噪声中音调检测任务的组合是否可以可靠且有效地预测听力损失中是否存在传导成分。作者假设，电池测试的性能将根据听力损失类型而有所不同。次要目的是评估新型自动听力测试算法的可靠性和有效性，以评估其是否适合纳入测试电池。
参与者接受了一系列听力评估，这些评估以随机顺序进行：手动纯音空气传导听力测试和骨传导听力测试；自动纯音空气传导听力测试；以及自动噪声中音调检测任务。每个自动测试均进行两次。使用手动听力测试的结果评估自动测试电池的能力：（a）预测空气骨导间隙（ABG）的存在；（b）准确测量 AC 听力阈值。测试-再测试条件进行了比较，以确定自动测试电池的每个组件的可靠性。从正常听力和传导性、感音神经性和混合性听力损失亚组中收集了 120 只耳朵的数据。
观察到不同类型听力损失之间的性能差异。尽管在安静状态下阈值受损，但具有传导成分的耳朵（传导性和混合性耳朵）的信噪比（SNR）往往正常，而没有传导成分的耳朵（正常和感音神经性耳朵）则表现出阈值与实现的 SNR 之间呈递增关系。使用无传导成分耳朵之间的这两个测量值之间的关系作为基准，可以根据该基准的偏差来估计耳朵是否具有传导成分。测试电池的灵敏度和特异性取决于此偏差的大小，但是随着 ABG 尺寸的增加、测试频率的降低以及考虑到多个测试频率的结果而增加。组成电池的各个自动测试被发现是可靠和有效的，测试和再测试结果之间具有很强的显著相关性（r = 0.81 至 0.99；p < 0.0001），并且自动和手动听力测试程序之间也具有很强的显著相关性（r = 0.98 至 0.99；p < 0.0001）。
仅使用 AC 测试即可以相当高的准确度预测 ABG 的存在。这种测试电池的应用包括骨传导听力测试或专用诊断设备不可用或不切实际的任何临床环境。这些应用的示例包括自动进行原位听力测试的自配助听器；在临床和家庭环境中进行的成人听力筛查；大型工业听力保护计划；以及环境噪声水平超过未封闭耳朵最大允许水平的测试环境。
