PROBLEM TO BE SOLVED: To provide a magnetic resonance imaging (MRI) apparatus capable of controlling the howling according to the change of the environment inside a gantry, relieving the mental stress from a subject and permitting comfortable dialogue.SOLUTION: A voice control part 15 of the MRI apparatus comprises a message transmitting (or message receiving) A-D converter 21 (or 26) for A-D converting voice signals from an operator (or a subject) a transmitting (receiving) howling detection/control part 22 (or 27) for outputting a howling controlling coefficient 23 (or 28) an adder 32 (or 33) for adding output signals from the A-D convertor 21 (or 26) and the control part 22 (or 27) a transmitting (receiving) D-A convertor 24 (or 29) for D-A converting voice signals and a transmission switch part 25 for permitting transmission by a transmission switching signal 20 from a transmission switch. The control part 22 (or 27) compares the transmitted and received voice data, analyzes the frequency, etc. in a determination possible period not to affect the dialogue, and outputs the howling controlling coefficient 23 (or 28).COPYRIGHT: (C)2009,JPO&INPIT【課題】ガントリー内の環境変化に追随したハウリング抑制をし、被検者の精神的負担を軽減し、快適な対話が可能なMRI装置を実現する。【解決手段】音声制御部15は操作者(被検者)からの音声信号をAD変換する送話(受話)AD変換器21(26)と、ハウリング抑制係数23(28)を出力する送話(受話)ハウリング検出/抑制22(27)と、AD変換器21(26)の出力信号と抑制部22(27)の出力信号との加算器32(33)と、音声信号をDA変換する送話(受話)DA変換器24(29)と、送話スイッチからの送話切換信号20により送話可能状態にする送話切換部25とを備える。抑制部22(27)は送受話の互いの音声データを比較し対話に影響を与えない判定可能時間に周波数等を分析しハウリング抑制係数23(28)を出力する。【選択図】図3
