Downloaded it on my phone; it's fine, just a video inside.
The sound isn't amazingly clear; you'd be better opening the bonnet and leaving the phone outside somewhere in the engine bay (not on top of the engine) on record..
..but it sounds like the starter motor isn't engaging properly and is grinding something rather than turning the engine over. Sometimes, perhaps, the gearing catches properly and turns the engine over so it starts normally.
Does the engine run fine and normally if you bump start it?*
Have a helper turn the engine over while you look/record. Can you see anything (belts/wheels/pulleys) moving when the starter is operated and that sound is heard?
* If you never bump started a car before:
- turn the key to the position just before the spring loaded position that operates the starter motor so all the dash lights come on
- depress the clutch pedal and keep it held down put the car in second gear
- roll the car down a hill or have a helper push the car to about 5 mph
- lift the clutch pedal up all the way and then immediately depress it all the way to the floor again and hold it there. If no joy, repeat in first gear
