我正在尝试计算WER来评估ASR系统,但是分数的计算却要花费很多时间(因为我想对其进行一些引导以获取置信区间以更可靠地评估系统)。

这是我到目前为止提出的代码,有没有人看到一种更有效的方法(更快,并且如果您有提高内存效率的想法,那也将受到欢迎)。

def modify_text(text):
    """
    Function to modify a clean text to add some errors in it.
    """
    modified_text = []
    for word in true_text:
        action = np.random.choice(['deletion','addition','subsitution','nothing'],
                                   p = [0.1,0.1,0.1,0.7])
        if action in ['addition','substitution']:
            modified_text.append(random.choice(voca))
        if action in ['addition','nothing']:
            modified_text.append(word)
    return modified_text

def wer(s1,s2):

    d = np.zeros([len(s1)+1,len(s2)+1])
    d[:,0] = np.arange(len(s1)+1)
    d[0,:] = np.arange(len(s2)+1)

    for j in range(1,len(s2)+1):
        for i in range(1,len(s1)+1):
            if s1[i-1] == s2[j-1]:
                d[i,j] = d[i-1,j-1]
            else:
                d[i,j] = min(d[i-1,j]+1, d[i,j-1]+1, d[i-1,j-1]+1)

    return d[-1,-1]/len(s1)

text = """I am happy to join with you today in what will go down in history as
the greatest demonstration for freedom in the history of our nation.
Five score years ago, a great American, in whose symbolic shadow
we stand today, signed the Emancipation Proclamation. This momentous
decree came as a great beacon light of hope to millions of Negro slaves
who had been seared in the flames of withering injustice. It came as a
joyous daybreak to end the long night of their captivity. """

true_text = list(tokenize(text))
modified_text = modify_text(true_text)
%timeit wer(true_text,modified_text)


输出:

7.04 ms ± 49.4 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)


好的,这似乎还不错,但是我有数以万计的文本需要使用引导程序进行评估,并且文本的长度更长。因此,我想找到一种更快的方法来执行wer功能。任何的想法?

最佳答案

大多数语音识别评估首先将语音分为句子或话语。然后,通过对齐每个发音来计算WER。因为WER计算为O(n ^ 2),所以可以大大提高速度。

10-08 08:41