Speech sound intelligibility assessment system, and method and program therefor

A speech sound intelligibility assessment method comprising the steps of:

• providing a speech sound database retaining a plurality of speech sounds;
• determining a speech sound to be presented by referring to the speech sound database;
• presenting the determined speech sound to a user;
• measuring an electroencephalogram signal of the user;
• 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;
• 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
• evaluating whether the user has clearly aurally comprehended the presented speech sound or not based on a result of determination of presence or absence of the positive component and a result of determination of presence or absence of the negative component.

A computer program, stored on a non-transitory computer-readable medium, to be executed by a computer mounted in a speech sound intelligibility assessment system including a speech sound database retaining a plurality of speech sounds, wherein

• the computer program causes the computer in the speech sound intelligibility assessment system to execute the steps of:
• determining a speech sound to be presented by referring to the speech sound database;
• presenting the determined speech sound to a user;
• measuring an electroencephalogram signal of the user;
• 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;
• 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
• evaluating a speech sound intelligibility indicating whether the user has clearly aurally comprehended the presented speech sound or not based on a result of determination of presence or absence of the positive component and a result of determination of presence or absence of the negative component.

A speech sound intelligibility assessment apparatus comprising:

• a presented-speech sound control section for determining a speech sound to be presented by referring to a speech sound database retaining a plurality of speech sounds;
• a positive component determination section for determining presence or absence of a positive component of an event-related potential in an electroencephalogram signal of a user measured by a biological signal measurement section in a zone from 600 ms to 800 ms from a starting point, the starting point being a point in time at which the speech sound is presented;
• a negative component determination section for determining presence or absence of a negative component in 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 a speech sound is presented by an output section;
• 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.

A method of operating a speech sound intelligibility assessment system, comprising:

• a step where a presented-speech sound control section determines a speech sound to be presented by referring to a speech sound database retaining a plurality of speech sounds;
• a step where an output section presents the determined speech sound to a user;
• a step where an electroencephalogram measurement section measures an electroencephalogram signal of the user;
• a step where a positive component determination section determines 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 step where a negative component determination section determines 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 step where a speech sound intelligibility assessment section evaluates whether the user has clearly aurally comprehended the presented speech sound or not based on a result of determination of presence or absence of the positive component and a result of determination of presence or absence of the negative component.

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;
• and
• a stimulation speech sound gain adjustment section for, when the positive component is absent and the negative component is absent, increasing the gain for the entire frequency band;
• or when the positive component is absent and the negative component is present, calculating a consonant frequency band of the speech sound and increasing the gain for the consonant frequency band.