11. The system according to claim 8 , wherein the additional text data further comprises at least one sentence having at least one word which was erroneously detected as the target keyword by the automatic speech recognition.
11. The system according to claim 8 , wherein the additional text data further comprises at least one sentence having at least one word which was erroneously detected as the target keyword by the automatic speech recognition. 12. The system according to claim 11 , wherein the discount parameter for the target keyword is tuned to be smaller to increase n-gram counts of each word which was erroneously detected as the target keyword.