Of a software that transforms the counting syllables slowly automatically from a word in audio at normal speed.
Suppose I want to do that with audios from this page
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I assume that you are not asking how you, yourself, can talk slowly, you want to hear recordings stretched out. The first thing is to get the sound file itself, which in the case of Forvo is not trivial, but not impossible. Let's just assume that you have a sound file on your computer. The program Speech Analyzer has 'slowing down' as a built-in slider-type function in its player, so you can play back (the file or selection) at rates between 10% and 333% of recorded speed (at those margins the distortion is fairly extreme).
This can also be done in Praat, using Convert-Length(overlap-add) and setting a suitable factor (2 or 3 are reasonable, 4+ gets strange and also you lose the end of the recording: SA seems to implement this concept without the truncation). I will mention that Audacity has a Change Tempo function, but it's really not any good.