def METHOD_NAME(self, time_passed: float):
    s = time_passed * self.frequency
    s0 = int(s)
    s1 = s0 + 1
    k = 1.0 if self.loop else self._decay(time_passed)
    return (self._x_noise(s0) + (s - s0) * (self._x_noise(s1) - self._x_noise(s0))) * k