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谱减法和维纳滤波测验

了解频谱减法和维纳滤波如何估计噪声、处理 STFT 频谱以及如何利用信号失真与残余噪声进行权衡。

相关引导路径谱减法和维纳滤波
问题 1 的 8

光谱减法通常会带来哪些恼人的伪像？

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  1. 光谱减法通常会带来哪些恼人的伪像？
    • 音乐噪音（随机转瞬即逝的音调）
    • 回声消除
    • 体积标准化
    • 变调
  2. 谱减法和维纳滤波主要在哪个域中运行？
    • 仅原始时域
    • STFT 后的频域
    • 文本域
    • 图像域
  3. Under a specified statistical signal-and-noise model, what criterion does the classical Wiener estimator minimize?
    • The number of STFT frames
    • The file’s bit rate
    • Expected mean-squared estimation error
    • The number of microphones
  4. 谱减法通常如何估计噪声谱？
    • 来自随机数生成器
    • 从文字记录来看
    • 从信号最响亮的部分
    • 来自音频的无声或无声片段
  5. In the common power-spectrum Wiener gain G=Ps/(Ps+Pn), what do Ps and Pn denote?
    • Estimated clean-signal and noise powers in that frequency bin
    • Speech and noise sample counts
    • Two different phase angles
    • The number of filters and frames
  6. 是什么关键假设限制了这两种方法针对突然的声音（如关门声）？
    • 说话的声音总是很大
    • 噪声相对平稳
    • 只有一个发言者
    • 音频是立体声的
  7. What may happen to the estimated magnitude in a spectral-subtraction bin when the noise estimate exceeds the observation?
    • It is wrapped into a positive phase
    • It is replaced by a transcript token
    • The negative result is floored to zero
    • It is doubled to preserve loudness
  8. When a real-valued Wiener gain is applied to a complex noisy STFT coefficient, what is commonly done with its phase?
    • Phase is replaced by the text prompt
    • Phase is always set to zero
    • The coefficient is converted into a stereo channel
    • The noisy phase is retained while the magnitude is scaled