We bought a house about a year ago, one of the reasons we bought it was because it had an outdoor pool. The pool is walled, and part of the wall forms the back of our neighbours' house. They bought their house around the same time as we bought ours and there is no way they couldn't not have known they were metres from a pool.
They are a retired couple and we have 4 DC. A few weeks after we both moved into our properties the lady made a comment about the children being noisy in the pool. I knew then that we were likely to have a problem so we remind the children not to scream and shout when they're in the garden or pool.
We heat the pool for about 4 months over summer and the children use it whenever they can. Probably for up to two hours a day and never after 6pm. There is obviously some noise, laughter, shrieking, jumping in etc from the children. There certainly isn't any offensive language or screaming. Occasionally the children will have friends over and then there is probably a bit more shrieking but we're talking a couple of times a month at most. We were away all of July so there hasn't been any noise for the past 5 weeks.
It was my son's birthday yesterday and we had a party at home, the children all swam and the noise level admittedly was quite high. The neighbours called tonight to complain "it was unbearable and we had to go out". I apologised for the noise and for not warning them about the party. They went on to suggest we never have a children's party in the pool again which I objected to; one of our four DC is a summer baby and it's likely we'll have his party at home every year and that the children would use the pool. I promised to give them good notice next time and that it would only be an annual thing.
They then went on to complain of constant noise from the pool. I objected to this as I've already said it's for a couple of hours a day max, never in the evenings and we've been away for all of the summer holidays until now. During term time the children are obviously at school so it's only generally used at weekends. They said they the noise from the children ruins their enjoyment of their garden. I was polite and apologetic and even went as far as promising not to let the children in the pool next Sunday as they are apparently entertaining but my DH doesn't think I should have said that in case they take to entertaining on a daily basis!
I'm unsure what to do or where we stand. I don't want to fall out with our neighbours. They clearly find any noise from the pool irritating and I can't realistically eradicate the noise 