用Python创建和Qt准确的节拍器(Creating an accurate metronome

I'm trying to add a simple metronome to my cross-platform pyQt program, but having a lot of difficulty getting accurate timing. Playing the sound seems to work the best using PyGame's sound system. I tried Phonon, but it just wasn't consistent at all and QSound doesn't work at all on my system. I've tried handling timing with python's time library and using QTimers, but QTimeLine seems to work the best.

The timing at lower tempo is not too bad... still a hiccup here and there. Higher tempos are not accurate at all however.

Any ideas/suggestions would be greatly appreciated!

Here's some code:

class Metronome(object):
    def init_metronome(self):
        self.metronome_timer = QtCore.QTimeLine(100000)
        self.metronome_timer.valueChanged.connect(self.tick)
        self.metronome_timer.setCurveShape(3) #linear curve

        self.ui.pushButton_metronome.toggled.connect(self.toggle_metronome)
        self.ui.spinBox_metronome_bpm.valueChanged.connect(self.set_metronome_bpm)

        pygame.mixer.init()
        self.sound = pygame.mixer.Sound("./sounds/tick.wav")


    def toggle_metronome(self):
        if self.ui.pushButton_metronome.isChecked() == True:
            self.set_metronome_bpm()
            self.metronome_timer.start()
        else: 
            self.metronome_timer.stop()

    def set_metronome_bpm(self):
        bpm = self.ui.spinBox_metronome_bpm.value()
        self.metronome_timer.setUpdateInterval(60./bpm * 1000)

    def tick(self):
        QtCore.QCoreApplication.processEvents()
        self.sound.play()

我不是很熟悉Python和Qt的互动，但我确实有计时器和线程和Qt的经验。