Speech-sound distinguishing ability determination apparatus, speech-sound distinguishing ability determination system, hearing aid gain determination apparatus, speech-sound distinguishing ability determination method, and program thereof

A speech discrimination ability determination apparatus for use in a speech discrimination ability determination system that switches between:

• a first trial in which a first speech sound is output with a first occurrence frequency and the second speech sound is output with a second occurrence frequency different from the first occurrence frequency;
• and a second trial in which the first speech sound is output with the second occurrence frequency and the second speech sound is output with the first occurrence frequency, comprising:
• an event-related potential acquisition configured to acquire event-related potential contained in an electroencephalogram signal measured by a biological signal measurement section, the event-related potential acquisition section acquiring:
• an event-related potential based on a point of outputting the first speech sound being output with the first occurrence frequency as a starting point;
• an event-related potential based on a point of outputting the first speech sound being output with the second occurrence frequency as a starting point;
• an event-related potential based on a point of outputting the second speech sound being output with the first occurrence frequency as a starting point;
• and an event-related potential based on a point of outputting the second speech sound being output with the second occurrence frequency as a starting point;
• an MMN determination configured to acquire, with respect to each of the first speech sound and the second speech sound, difference information between the event-related potential acquired during its output with the first occurrence frequency and the event-related potential acquired during its output with the second occurrence frequency, and configured to determine whether a negative component exists in the difference information in predetermined time ranges after the first speech sound and the second speech sound are output;
• and
• a discrimination ability determination configured to determine that the user discriminates the first speech sound and the second speech sound when a determination result by the MMN determination section indicates that the negative component exists.

A hearing aid gain determination apparatus for use in a speech discrimination ability determination system that switches between:

• a first trial in which a first speech sound is output with a first occurrence frequency and the second speech sound is output with a second occurrence frequency different from the first occurrence frequency;
• and a second trial in which the first speech sound is output with the second occurrence frequency and the second speech sound is output with the first occurrence frequency, comprising:
• an event-related potential acquisition configured to acquire event-related potential contained in an electroencephalogram signal measured by a biological signal measurement section, the event-related potential acquisition section acquiring:
• an event-related potential based on a point of outputting the first speech sound being output with the first occurrence frequency as a starting point;
• an event-related potential based on a point of outputting the first speech sound being output with the second occurrence frequency as a starting point;
• an event-related potential based on a point of outputting the second speech sound being output with the first occurrence frequency as a starting point;
• and an event-related potential based on a point of outputting the second speech sound being output with the second occurrence frequency as a starting point;
• an MMN determination configured to acquire, with respect to each of the first speech sound and the second speech sound, difference information between the event-related potential acquired during its output with the first occurrence frequency and the event-related potential acquired during its output with the second occurrence frequency, and configured to determine whether a negative component exists in the difference information in predetermined time ranges after the first speech sound and the second speech sound are output;
• a discrimination ability determination configured to determine that the user discriminates the first speech sound and the second speech sound when a determination result by the MMN determination section indicates that the negative component exists;
• and
• a gain determination configured to determine, by referring to a predetermined determination criterion, a gain for a hearing aid based on the difference information.

A speech discrimination ability determination method comprising:

• by referring to a speech sound database storing information of a plurality of speech sounds, determining a first speech sound and a second speech sound which are different from each other;
• measuring an electroencephalogram signal of a user;
• performing a first trial in which the first speech sound is output with a first occurrence frequency and the second speech sound is output with a second occurrence frequency different from the first occurrence frequency;
• performing a second trial in which the first speech sound is output with the second occurrence frequency and the second speech sound is output with the first occurrence frequency;
• acquiring event-related potential contained in the electroencephalogram signal, the step acquiring:
• an event-related potential based on a point of outputting the first speech sound being output with the first occurrence frequency as a starting point;
• an event-related potential based on a point of outputting the first speech sound being output with the second occurrence frequency as a starting point;
• an event-related potential based on a point of outputting the second speech sound being output with the first occurrence frequency as a starting point;
• and an event-related potential based on a point of outputting the second speech sound being output with the second occurrence frequency as a starting point;
• with respect to each of the first speech sound and the second speech sound, acquiring difference information between the event-related potential acquired during its output with the first occurrence frequency and the event-related potential acquired during its output with the second occurrence frequency, and determining whether a negative component exists in the difference information in predetermined time ranges after the first speech sound and the second speech sound are output;
• and
• when a determination result by the determining step indicates that the negative component exists, determining that the user discriminates the first speech sound and the second speech sound.

A computer program stored on a non-transitory computer-readable medium, and to be executed by a computer mounted in a speech discrimination ability determination apparatus of a speech discrimination ability determination system,

• wherein the computer program causes the computer to execute:
• receiving an electroencephalogram signal of a user measured by a biological signal measurement section;
• by referring to a speech sound database storing information of a plurality of speech sounds, determining a first speech sound and a second speech sound which are different from each other;
• performing a first trial in which the first speech sound is output with a first occurrence frequency and the second speech sound is output with a second occurrence frequency different from the first occurrence frequency;
• performing a second trial in which the first speech sound is output with the second occurrence frequency and the second speech sound is output with the first occurrence frequency;
• acquiring event-related potential contained in the electroencephalogram signal, the step acquiring:
• an event-related potential based on a point of outputting the first speech sound being output with the first occurrence frequency as a starting point;
• an event-related potential based on a point of outputting the first speech sound being output with the second occurrence frequency as a starting point;
• an event-related potential based on a point of outputting the second speech sound being output with the first occurrence frequency as a starting point;
• and an event-related potential based on a point of outputting the second speech sound being output with the second occurrence frequency as a starting point;
• with respect to each of the first speech sound and the second speech sound, acquiring difference information between the event-related potential acquired during its output with the first occurrence frequency and the event-related potential acquired during its output with the second occurrence frequency, and determining whether a negative component exists in the difference information in predetermined time ranges after the first speech sound and the second speech sound are output;
• and
• when a determination result by the MMN determination section indicates that the negative component exists, determining that the user discriminates the first speech sound and the second speech sound.