Cognitive function evaluation device, cognitive function evaluation system, and cognitive function evaluation method

A cognitive function evaluation method, comprising:

• displaying, with a display device, task information for a speech uttered by a subject, the task information including displayed text of one or more of a tongue twister, and random vowels particular to a memory of the subject;
• obtaining speech data using a sound collection device including a microphone, the speech data indicating the speech uttered by the subject into the microphone, the sound collection device including a sound barrier surrounding the microphone;
• extracting a plurality of vowels from the speech data obtained in the obtaining, and calculating, for each of the plurality of vowels, a feature value based on a frequency and an amplitude of at least one formant obtained from a spectrum of the vowel;
• evaluating a cognitive function of the subject from the feature value calculated in the calculating,
• outputting an evaluation result and an image of the evaluation result using the display device,
• and outputting, using the display device, a recommendation to seek medical attention alongside the image of the evaluation result, the recommendation based on the evaluation result;
• wherein the calculating includes:
• calculating frequencies and amplitudes of a plurality of second formants at predetermined time intervals in the spectrum, as the frequency and the amplitude of the at least one formant;
• and
• calculating, as the feature value, an amount of change over time of the frequencies and the amplitudes of the plurality of second formants calculated.

A cognitive function evaluation device, comprising:

• a display device configured to display task information for a speech uttered by a subject, the task information including displayed text of one or more of a tongue twister, and random vowels particular to a memory of the subject;
• an obtainment unit operably connected to a sound collection device including a microphone, the obtainment unit configured to obtain speech data indicating the speech uttered by the subject;
• wherein the sound collection device includes a sound barrier surrounding the microphone;
• a processor configured to,
• extract a plurality of vowels from the speech data obtained by the obtainment unit,
• calculate, for each of the plurality of vowels, a feature value based on a frequency and an amplitude of at least one formant obtained from a spectrum of the vowel, and
• evaluate a cognitive function of the subject from the feature value calculated;
• and
• an output unit configured to output an evaluation result of the processor and an image of the evaluation result using the display device, the obtainment unit further configured to display to the subject a recommendation to seek medical attention alongside the image of the evaluation result, the recommendation based on the evaluation result;
• wherein the processor is configured to:
• calculate a frequency and an amplitude of a first formant and a frequency and an amplitude of a second formant from the spectrum, as the frequency and the amplitude of the at least one formant;
• and
• calculate the frequency of the second formant relative to the frequency of the first formant and the amplitude of the second formant relative to the amplitude of the first formant, as the feature value.