6. The operator evaluation support method according to claim 5 , further comprising: referring to the speech recording unit recording an average-volume-in-speech in association with the speech time of the customer, acquiring the average-volume-in-speech of the speech of the customer that has started after the superposition speech from the speech recording unit, comparing the average-volume-in-speech of the speech of the customer that has started after the superposition speech with a standard average volume, and identifying the superposition speech as the problematic superposition speech when the average-volume-in-speech of the speech of the customer that has started after the superposition speech is higher than the standard average volume.
6. The operator evaluation support method according to claim 5 , further comprising: referring to the speech recording unit recording an average-volume-in-speech in association with the speech time of the customer, acquiring the average-volume-in-speech of the speech of the customer that has started after the superposition speech from the speech recording unit, comparing the average-volume-in-speech of the speech of the customer that has started after the superposition speech with a standard average volume, and identifying the superposition speech as the problematic superposition speech when the average-volume-in-speech of the speech of the customer that has started after the superposition speech is higher than the standard average volume. 7. The operator evaluation support method according to claim 6 , further comprising: referring to the speech recording unit with respect to the telephone call, calculating an average value of the average-volume-in-speeches of the customer, and setting the average value as the standard average volume.