The children's mother, 36-year-old Beth Chappel, said of the Mitchells: "They're really nasty people."
One of Chappel's friends added: "Beth's children have been in the tears because the sound gets to them so much. The Mitchells have had it switched on for long periods so you cannot get away from it."
Kathryn Mitchell has argued that the device is necessary to keep the peace. "For the last two years life has been pretty unbearable. That woman and her kids have made our lives a living hell," she said. "Buying the device was a last resort and we have checked that it is 100 per cent legal."
Ipswich Borough Council has warned the Mitchells that they will be issued with a Community Protection Notice if they use the device again. If they breach the notice they face being taken to court and fined up to 2500 each.
Michael Mitchell defended his actions, saying: "I would never do anything to hurt a child deliberately."