问我的笔记检测算法在少数情况下失败了吗？

EN

window_size = 2000    # Size of window to be used for detecting silence
beta = 1   # Silence detection parameter
max_notes = 100    # Maximum number of notes in file, for efficiency
sampling_freq = 44100   # Sampling frequency of audio signal
threshold = 200


 # traversing sound_square array with a fixed window_size
while(i<=len(sound_square)-window_size):
    s = 0.0
    j = 0
    while(j<=window_size):
        s = s + sound_square[i+j]
        j = j + 1   
        # detecting the silence waves
    if s < threshold:
        if(i-k>window_size*4):
            dft = np.array(dft) # applying fourier transform function
            dft = np.fft.fft(sound[k:i])
            dft = np.argsort(dft)

            if(dft[0]>dft[-1] and dft[1]>dft[-1]):
                i_max = dft[-1]
            elif(dft[1]>dft[0] and dft[-1]>dft[0]):
                i_max = dft[0]
            else :  
                i_max = dft[1]
                        # claculating frequency             
            frequency.append((i_max*sampling_freq)/(i-k))
            dft = []
            k = i+1
    i = i + window_size