Patent ID: 8849391

Claim:
A speech sound intelligibility assessment system comprising: a speech sound database retaining a plurality of speech sounds; a presented-speech sound control section for determining a speech sound to be presented by referring to the speech sound database; an output section for presenting the determined speech sound to a user; a biological signal measurement section for measuring an electroencephalogram signal of the user; a positive component determination section for determining presence or absence of a positive component of an event-related potential in the electroencephalogram signal in a zone from 600 ms to 800 ms from a starting point, the starting point being a point in time at which the output section presents a speech sound; a negative component determination section for determining presence or absence of a negative component of an event-related potential in the electroencephalogram signal in a zone from 100 ms to 300 ms from a starting point, the starting point being a point in time at which the output section presents a speech sound; and a speech sound intelligibility assessment section for evaluating whether the user has clearly aurally comprehended the presented speech sound or not, based on a result of determination as to presence or absence of the positive component acquired from the positive component determination section and a result of determination as to presence or absence of the negative component acquired from the negative component determination section; wherein the speech sound intelligibility assessment section: makes an evaluation that the user has clearly aurally comprehended the presented speech sound when the result of determination by the positive component determination section indicates that the positive component is absent; makes an evaluation that the user has not clearly aurally comprehended the presented speech sound due to an insufficient overall sound pressure when the result of determination by the positive component determination section indicates that the positive component is present and the result of determination by the negative component determination section indicates that the negative component is absent; or makes an evaluation that the user has not clearly aurally comprehended the presented speech sound due to an insufficient sound pressure of a consonant frequency when the result of determination by the positive component determination section indicates that the positive component is present and the result of determination by the negative component determination section indicates that the negative component is present.