We also put a ring door bell or camera on the front and back of the property with smoke sensors and decibel sensors on the interior to record high levels of noise or smoking. 

Because here is why government interference and leftist politics result in a much POORER world than free market politicsSocialism in all forms REWARDS FAILURE AND PUNISHES SUCCESSIts about INCENTIVEEverything else is just noise

They make fancier ones that include "crackle" noises and make it more realistic.

You can place motion sensors and noise sensors inside the property. 

Save your texts and such with your tenant and your calls to the police— build a record of your neighbor’s noise.

Add compression, noise reduction, bass, EQ to your voice to make it sound real good and real crisp3.

These people add much noise to the entire market while doing little to actually move things along.Furthermore, they really just pull funds from sellers since the only way they are remotely a deal is if they are lowballed to sh$t so they can make their spread.

Potential for Permit Revocation: Non-compliance with noise ordinances, occupancy limits, or HOT reporting can result in permit revocation.

They don't bother me, but many guests freak over them.Awkward living-room layout that makes it nearly impossible to watch TV.Passageway of about 10" into dining room.Cupboard that opens on, and is only accessible from, the living room rather than the kitchen.Basement apartment = noise upstairs.

One failure shouldn't cause you to stop using them.They are available at WalMart.com now, so you could return them easier.Loud fans may hide noises, but it also means it is inefficient.