How lovely that you have hogs in the garden. The noise was probably the female ‘huffing’ during the courtship circling procedure.
You could try to build a hog house for them. There’s some information in this link https://www.hedgehogstreet.org/help-hedgehogs/hedgehog-homes/
It’s really important for hogs to have access to water all day every day, because they often cannot find it elsewhere. I use large (approx. at least 10″ across) plant sauchers. Hogs are very good at spilling water if the saucers are too small – they have a habit of just walking through it – why waste all that energy walking round! The saucers double up for baths for the birds, during the day.
If you are going to feed the hogs, most bird food isn’t good for them. It’s best to give them either cat/dog food, cat/kitten bisuits or hedgehog food. I recently discovered that a rat visiting here didn’t like kitten biscuits, which I was quite pleased about. Although with all those cats, that might be a problem – but you may be able to make a cat proof feeding station. The cats won’t bother the hogs, other than potentially eating their food.
Good luck. I hope you continue to enjoy the hogs’ visits. Happy hog watching!