1. An annoyance judgment system comprising: one or more memories storing a speech sound database retaining a plurality of monosyllabic speech sounds such that, for each speech sound, the speech sound and a reference latency of an electroencephalogram negative component corresponding to the speech sound are retained in association; and circuitry which in operation is configured to: measure an electroencephalogram signal of a user; determine a monosyllabic speech sound to be presented by referring to the speech sound database; present the determined speech sound to the user; judge annoyance of the output speech sound by comparing a peak latency of a negative component of the measured electroencephalogram signal in a range from 50 ms to 350 ms from a starting point, the starting point being a point in time at which the speech sound is presented, against the reference latency corresponding to the determined speech sound that is retained in the speech sound database; and output gain settings for presenting speech sounds based on the annoyance judgment.
1. An annoyance judgment system comprising: one or more memories storing a speech sound database retaining a plurality of monosyllabic speech sounds such that, for each speech sound, the speech sound and a reference latency of an electroencephalogram negative component corresponding to the speech sound are retained in association; and circuitry which in operation is configured to: measure an electroencephalogram signal of a user; determine a monosyllabic speech sound to be presented by referring to the speech sound database; present the determined speech sound to the user; judge annoyance of the output speech sound by comparing a peak latency of a negative component of the measured electroencephalogram signal in a range from 50 ms to 350 ms from a starting point, the starting point being a point in time at which the speech sound is presented, against the reference latency corresponding to the determined speech sound that is retained in the speech sound database; and output gain settings for presenting speech sounds based on the annoyance judgment. 7. The annoyance judgment system of claim 1 , wherein the one or more memories further stores a result accumulating database configured to accumulate information indicating a result of annoyance judgment for the speech sound, wherein the result accumulating database accumulates information indicating the result of annoyance judgment for the speech sound with respect to a consonant, or a group of speech sounds whose differences in reference latency is smaller than a predetermined value.