PROBLEM TO BE SOLVED: To achieve inexpensive and highly accurate mastication detection in which mastication detection is performed using mastication sound measured by a microphone or the like.SOLUTION: A form of a power transition in the time direction of mastication sound measured in a mastication sound measurement section is obtained, and mastication is determined on the basis of the form. For instance, a power threshold and a time threshold are applied to the form, and a portion in the form where a power which is larger than the power threshold is held for a period between a lower limit time threshold and an upper limit time threshold is determined as a mastication portion. Further, for instance, a background noise level may be estimate to correct the power threshold. For instance, further, a band pass filter whose pass band is a frequency band including many mastication sound components may be provided on the output side of the mastication sound measurement section. Further, in addition, ambient noise may measured and ambient noise components included in output signals of the mastication sound measurement section may be suppressed and used.COPYRIGHT: (C)2013,JPO&INPIT【課題】低コストで高精度な咀嚼検出を可能とする。【解決手段】咀嚼音計測部で計測された咀嚼音の時間方向のパワー推移の概形を求め、この概形に基づいて咀嚼を判定する。例えば、概形に、パワー閾値および時間閾値を適用し、概形においてパワー閾値より大きなパワーが下限時間閾値および上限時間閾値の間の時間だけ持続する部位を咀嚼部位と判定する。例えば、さらに、暗騒音レベルを推定してパワー閾値を補正するようにしてもよい。例えば、さらに、咀嚼音計測部の出力側に、咀嚼音成分が多く含まれる周波数帯域を通過帯域とするバンドパスフィルタを備えてもよい。例えば、さらに、環境雑音を測定し、咀嚼音計測部の出力信号に含まれる環境雑音成分を抑圧して、使用するようにしてもよい。【選択図】図1
