I tried to edit my post and then it disappeared so here goes
Good morning
I assume you want to deter cats from coming into your garden to eat the food you put out for the hedgehogs. I don’t know anything about sonic repellents ( but I see Nic has responded). My point is that if you feed one species you invariably attract others I have found that the only way to deter unwanted species is to adapt how you feed them. I think Nic’s suggestion of a feeding station is a good one but wouldn’t work for me as in my case it was rats, so I have had to feed the birds using cages, trays etc and subsequently lost out getting a daily visit from the squirrels. In terms of the hedgehogs it is supervising their nightly feeds from March until November or whenever their visits stop ( this is a real commitment as I never miss a night, so I have to holiday in the winter months) but the pleasure I derive is worth every second of getting wet and cold. Luckily I am retired as I couldn’t have provided this service if I was working. I hope you resolve your problem. Best wishes
