Flexslider - different slideshow speed on each slide

I'm using Flexslider and have been asked to display each slide at a different time depending on how much content it has, so fast for a short sentence and slow for a paragraph. How can I set this up when flexslide allows just 1 Slideshowspeed value. My code:

$(window).load(function() {
        $('#flexslider1').flexslider({
        easing: "swing",  
        animation: "fade",
        slideshowSpeed: 7000,
        animationSpeed: 600,
        startAt: 0,
        initDelay: 0,
        controlNav: true,
        directionNav: true,
        pausePlay: true,
        pauseText: 'Pause',
        playText: 'Play'
    }); 
});