Without question, criminal defendants are constitutionally and statutorily entitled to a speedy trial. U.S. Const. Amend. VI; Tenn. Const. Art. I, 9; Tenn. Code Ann. 40-14-101. There is no set time limit within which the trial must commence; rather, consideration must be given to the circumstances of each case. The right to a speedy trial is implicated when there is an arrest or a formal grand jury accusation. State v. Utley, 956 S.W.2d 489, 491 (Tenn. 1997). When an appellant claims a denial of this right, the reviewing court must conduct the balancing test set forth in Barker v. Wingo, 407 U.S. 514, 92 S. Ct. 2182, 33 L. Ed. 2d 101 (1972), to determine whether the right to a speedy trial has been violated. State v. Wood, 924 S.W.2d 342, 346 (Tenn. 1996); State v. Baker, 614 S.W.2d 352, 353 (Tenn. 1981); State v. Bishop, 493 S.W.2d 81, 83-85 (Tenn. 1973). If, after conducting this balancing test, it is concluded that the appellant was in fact denied a speedy trial, constitutional principles require that the conviction be reversed and the criminal charges dismissed. Bishop, 493 S.W.2d at 83. In conducting this balancing test, we are required to examine the conduct of both the prosecution and the appellant, focusing primarily on: (1) the length of the delay; (2) the reason for the delay; (3) whether appellant asserted his right to a speedy trial; (4) whether appellant was prejudiced by the delay. Wood, 924 S.W.2d at 345; Bishop, 493 S.W.2d at 84; State v. Jefferson, 938 S.W.2d 1, 12-13 (Tenn. Crim. App. 1996); State v. Vance, 888 S.W.2d 776, 778 (Tenn. Crim. App. 1994). The most important factor is whether the defendant was prejudiced by the delay. Vance, 888 S.W.2d at 778. the most important inquiry with regard to prejudice is whether the delay impaired the defendant's ability to prepare a defense. Id. a delay of as long as two years standing alone will not support a finding of a speedy trial violation. Id. Assertion of right to a speedy trial by an appellant is given great weight in the determination of whether the right was denied. Barker, 407 U.S. at 531-32, 92 S. Ct. 2192-93. "Failure to assert the right implies an appellant does not actively seek a swift trial." Wood, 924 S.W.2d at 348. However, when an accused is unaware of pending charges against him, failure to assert the right cannot be weighed against him. Doggett, 505 U.S. at 653-54, 112 S. Ct. at 2691.