Questionnaires for the Assessment of Cognitive Function Secondary to Intake Interviews in In-Hospital Work and Development and Evaluation of a Classification Model Using Acoustic Features

Abstract

The number of people with dementia is increasing each year, and early detection allows for early intervention and treatment. Since conventional screening methods are time-consuming and expensive, a simple and inexpensive screening is expected. We created a standardized intake questionnaire with thirty questions in five categories and used machine learning to categorize older adults with moderate and mild dementia and mild cognitive impairment, based on speech patterns. To evaluate the feasibility of the developed interview items and the accuracy of the classification model based on acoustic features, 29 participants (7 males and 22 females) aged 72 to 91 years were recruited with the approval of the University of Tokyo Hospital. The MMSE results showed that 12 participants had moderate dementia with MMSE scores of 20 or less, 8 participants had mild dementia with MMSE scores between 21 and 23, and 9 participants had MCI with MMSE scores between 24 and 27. As a result, Mel-spectrogram generally outperformed MFCC in terms of accuracy, precision, recall, and F1-score in all classification tasks. The multi-classification using Mel-spectrogram achieved the highest accuracy of 0.932, while the binary classification of moderate dementia and MCI group using MFCC achieved the lowest accuracy of 0.502. The FDR was generally low for all classification tasks, indicating a low rate of false positives. However, the FNR was relatively high in some cases, indicating a higher rate of false negatives.

Keywords: MFCC; audio processing; cognitive function; gerontology; intake interview; mel-spectrum.

Figure 1

(a) A table partitioned by an acrylic board. (b) The interviewer sat on the far side and the participant sat on the front side.

Figure 2

(a) Figure converted from a wav data file by MFCC. (b) Figure converted from a wav data file by Mel-spectrogram.

Figure 3

Comparison of classification accuracy between MFCC and Mel-spectrogram. Light gray represents MFCC and dark gray represents Mel-spectrogram.

Figure 4

Comparison of the seconds of silence between the (a) moderate and mild dementia groups, (b) moderate dementia and the MCI groups, and (c) mild dementia and MCI groups.