Vander Werff Kathy R
Department of Communication Sciences and Disorders, Syracuse University, Syracuse, NY 13244, USA.
J Am Acad Audiol. 2009 Jul-Aug;20(7):433-52. doi: 10.3766/jaaa.20.7.5.
The number of commercially available evoked potential systems implementing multiple-frequency auditory steady-state response (ASSR) techniques has increased over the last several years. The majority of data in the multiple-frequency ASSR literature have been obtained using time-domain averaging and Fast Fourier Transform (FFT) techniques with F-test statistical analysis. Another commercially available analysis method has been introduced using an adaptive filtering algorithm called the Fourier Linear Combiner (FLC). No previous investigation has evaluated the performance of the FLC method, nor compared the two techniques. In addition, there is a need for evaluation of clinical protocols for ASSR testing using these available commercial systems that balance time efficiency and accuracy in estimating threshold.
(1) To determine whether ASSR thresholds, the relationship between ASSR and behavioral thresholds, and clinical test time are affected by the ASSR analysis method when comparing two commercially available systems for multiple-frequency ASSR. (2) To investigate the use of clinical ASSR test protocols of varying recording length, and the effect on accuracy and time efficiency, using these two commercially available analysis methods. RESEARCH DESIGN AND STUDY SAMPLE: ASSR threshold searches were completed on a group of 20 normal-hearing and 20 hearing-impaired adult participants using two different analysis methods, FFT and FLC, under separate, independent, tests as well under simultaneous recording conditions.
Three experiments were completed: (1) independent assessment of ASSR thresholds using the FFT and FLC methods separately, (2) simultaneous recording of ASSR for both the FFT and FLC method, and (3) an automated threshold search protocol using the FLC method. Variables analyzed for Experiments 1 and 3 included ASSR thresholds, the difference between ASSR and behavioral threshold, and total test time. For Experiment 2, the number of detected ASSRs per method, the agreement between methods, and the time per detected ASSR were evaluated.
ASSR thresholds and the relationship between ASSR and behavioral thresholds were found to be in line with those reported in the literature for multiple-frequency ASSR for both the FLC and FFT methods. ASSR thresholds were found to be significantly higher for the FLC method for the low frequencies, but not for the high frequencies, when tested independently. Correlations between ASSR and behavioral thresholds, however, were found to be the same across methods. Overall, it did not appear that either analysis method held an advantage in terms of accuracy or overall test time in independent comparisons using the protocol implemented in the current study. The time benefits of an automated protocol were significant, although with compromised test accuracy. The results of this study suggest critical clinical decision making is a necessary part of the ASSR protocol in order to decrease false positive and false negative responses and to increase overall efficiency.
在过去几年中，采用多频听觉稳态反应（ASSR）技术的商用诱发电位系统数量有所增加。多频ASSR文献中的大多数数据是使用时域平均和快速傅里叶变换（FFT）技术以及F检验统计分析获得的。另一种商用分析方法已被引入，它使用一种称为傅里叶线性组合器（FLC）的自适应滤波算法。此前没有研究评估过FLC方法的性能，也没有对这两种技术进行比较。此外，需要评估使用这些现有商用系统进行ASSR测试的临床方案，这些方案要在估计阈值时平衡时间效率和准确性。
（1）在比较两种用于多频ASSR的商用系统时，确定ASSR分析方法是否会影响ASSR阈值、ASSR与行为阈值之间的关系以及临床测试时间。（2）使用这两种商用分析方法，研究不同记录长度的临床ASSR测试方案的使用情况以及对准确性和时间效率的影响。研究设计与样本：在20名听力正常和20名听力受损的成年参与者中，分别使用两种不同的分析方法，即FFT和FLC，在单独、独立测试以及同步记录条件下完成ASSR阈值搜索。
完成了三项实验：（1）分别使用FFT和FLC方法独立评估ASSR阈值，（2）同时记录FFT和FLC方法的ASSR，（3）使用FLC方法的自动阈值搜索方案。对实验1和3分析的变量包括ASSR阈值、ASSR与行为阈值之间的差异以及总测试时间。对于实验2，评估了每种方法检测到的ASSR数量、方法之间的一致性以及每个检测到的ASSR的时间。
发现FLC和FFT方法的ASSR阈值以及ASSR与行为阈值之间的关系与多频ASSR文献中报道的一致。在独立测试时，发现FLC方法在低频时的ASSR阈值显著更高，但高频时并非如此。然而，发现ASSR与行为阈值之间的相关性在不同方法中是相同的。总体而言，在使用本研究中实施的方案进行的独立比较中，似乎两种分析方法在准确性或总体测试时间方面都没有优势。自动方案的时间优势显著，尽管测试准确性有所下降。本研究结果表明，关键的临床决策是ASSR方案的必要组成部分，以便减少假阳性和假阴性反应并提高整体效率。
