Disturbance of the peace (noise protection)

For a given reason, which unfortunately has already been pointed out several times.
There are owners who do not abide by anything and even threaten their neighbours (threaten physical violence).

I can only advise all those who feel disturbed after being approached once by the disturber of the peace to call the police.

But here is some information:
Summer party. There are, however, a few objections.
“There is no specific ban and no law, but there are already laws on noise protection and inappropriate use of living space, which can cause damage to the building.
At night, the noise level in bedrooms must not exceed 25 dB(A).
If we exceed this level, we would be in breach of the regulations on night-time rest, which starts at 10pm and lasts until 8am. This is where the police can come in.

How do I measure the dB(A), with an app. e.g. on the IPhone:
Well suited to get a rough impression of the measuring point/measuring situation.
Simple protocol function.

https://apps.apple.com/de/app/schallmessung-sound-meter/id1452030239

Fulfils its purpose, the advertising is discreet and there are no Inapp purchases.