The fundamental frequency (F0) control in speech production has not yet been understood completely. There exists a rich variety of F0 patterns depending on a speech production style (i.e., emotional influence, dialects, speaker's intentions and habits, and so forth). These F0 patterns are controlled by the laryngeal mechanism. Part of this mechanism, the contraction of the cricothyroid muscle (CT) makes F0 rise, and the sternohyoid muscle (SH) movement causes F0 to fall. Up to now, few studies were made on F0 falling, but, in order to generate various F0 patterns, it is believed that it is necessary to control both the rise and fall of F0. Therefore a new F0 control model is proposed which has two parameters. The first parameter, Tau1, represents F0 rising, and the second parameter, Tau2, represents F0 falling. In addition, some primary results on controlling F0 by using the proposed model are included in this report. Currently, progressive studies on F0 patterns of the Osaka dialect are being made. The F0 falling patterns in the Osaka dialect are more frequently observed. By applying the proposed model to the utterance of the Osaka dialect, the flexibility of the proposed model could be examined.