Department of Electrical Engineering, Federal Institute of Education Science and Technology of Minas Gerais-Ipatinga Campus, Maria Silva, 125, CEP, Ipatinga, MG, 35164-261, Brazil.
Department of Electrical Engineering, Federal Institute of Education Science and Technology of Espírito Santo-São Mateus Campus, São Mateus, ES, Brazil.
Med Biol Eng Comput. 2021 Feb;59(2):391-399. doi: 10.1007/s11517-021-02323-z. Epub 2021 Jan 25.
Auditory steady-state response (ASSR) is useful for hearing threshold estimation. The ASSR is usually detected with objective response detectors (ORD). The performance of these detectors depends on the signal-to-noise ratio (SNR) as well as the signal length. Since it is undesirable to increase the signal length, then, this work provides a multivariate technique for improving the SNR and consequently the detection power. We propose the insertion of a short calibration step before the detection protocol, in order to perform a search among the available electroencephalogram (EEG) derivations and select the derivation with the highest SNR. The ORD used in this work was the magnitude-squared coherence (MSC). The standard detection protocol is to use the same EEG derivation in all exams. Using 22-scalp positions, the new technique achieved a detection rate higher than that obtained in 99.13% of the standard detection protocol. When restrictions were applied to the search, a superior performance was achieved. Thus, the technique proposed was able to track the best EEG derivations before exams and seems to be able to deal with the variability between individuals and between sessions.
听觉稳态反应（ASSR）可用于听力阈值估计。ASSR 通常使用客观反应探测器（ORD）进行检测。这些探测器的性能取决于信噪比（SNR）和信号长度。由于增加信号长度是不可取的，因此，这项工作提供了一种用于提高 SNR 并进而提高检测能力的多变量技术。我们建议在检测协议之前插入一个短的校准步骤，以便在可用的脑电图（EEG）衍生中进行搜索，并选择具有最高 SNR 的衍生。本工作中使用的 ORD 是幅度平方相干性（MSC）。标准检测协议是在所有检查中使用相同的 EEG 衍生。使用 22 个头皮位置，新的技术实现了高于标准检测协议 99.13%的检测率。当对搜索施加限制时，获得了更好的性能。因此，所提出的技术能够在检查前跟踪最佳的 EEG 衍生，并似乎能够处理个体之间和会话之间的可变性。
