Johns Hopkins University School of Medicine, Department of Otolaryngology - HNS, Center for Hearing and Balance, 515 Traylor, 720 Rutland Ave., Baltimore, MD 21205, United States.
Hear Res. 2013 Apr;298:73-9. doi: 10.1016/j.heares.2013.01.002. Epub 2013 Jan 21.
The notched noise method is an effective procedure for measuring frequency resolution and auditory filter shapes in both human and animal models of hearing. Briefly, auditory filter shape and bandwidth estimates are derived from masked thresholds for tones presented in noise containing widening spectral notches. As the spectral notch widens, increasingly less of the noise falls within the auditory filter and the tone becomes more detectible until the notch width exceeds the filter bandwidth. Behavioral procedures have been used for the derivation of notched noise auditory filter shapes in mice; however, the time and effort needed to train and test animals on these tasks renders a constraint on the widespread application of this testing method. As an alternative procedure, we combined relatively non-invasive auditory brainstem response (ABR) measurements and the notched noise method to estimate auditory filters in normal-hearing mice at center frequencies of 8, 11.2, and 16 kHz. A complete set of simultaneous masked thresholds for a particular tone frequency were obtained in about an hour. ABR-derived filter bandwidths broadened with increasing frequency, consistent with previous studies. The ABR notched noise procedure provides a fast alternative to estimating frequency selectivity in mice that is well-suited to high through-put or time-sensitive screening.
切口噪声法是一种在人类和动物听觉模型中测量频率分辨率和听觉滤波器形状的有效方法。简而言之，听觉滤波器形状和带宽估计是从在包含变宽频谱切口的噪声中呈现的音调的掩蔽阈值中得出的。随着频谱切口变宽，噪声中越来越少的部分落在听觉滤波器内，音调变得更容易察觉，直到切口宽度超过滤波器带宽。在小鼠中，已经使用行为程序来推导切口噪声听觉滤波器形状；然而，在这些任务上训练和测试动物所需的时间和精力限制了这种测试方法的广泛应用。作为替代程序，我们将相对非侵入性的听觉脑干反应（ABR）测量与切口噪声方法相结合，以估计在 8、11.2 和 16 kHz 中心频率下正常听力小鼠的听觉滤波器。大约在一个小时内获得了特定音调频率的完整的一组同时掩蔽阈值。ABR 衍生的滤波器带宽随频率增加而变宽，与先前的研究一致。ABR 切口噪声程序为在小鼠中估计频率选择性提供了一种快速替代方法，非常适合高通量或时间敏感的筛选。
