Noise and Smoke Monitoring: The Security Standard We Run on Every Property

A noise alert at 1am is only worth what happens in the next ten minutes. The device is the cheap part. What decides whether a gathering turns into a police visit, a fine, or a one star review is whether somebody is awake, watching the dashboard, and authorised to act on it.

Our team manages 300+ properties across 50+ cities and 7 countries, and noise and smoke monitoring is a standard line in that setup rather than something an owner adds after a bad weekend. Here is how we specify the devices, where they go, and what actually happens when one of them fires.

What the Device Measures, and What It Does Not

A noise monitor does not record audio and it does not capture conversations. It measures decibel levels in a room and compares them against a threshold set on a dashboard. Cross the threshold and the guest gets an automated text asking them to bring it down. No camera, no recording, no listening in. That is why these devices are legal and widely accepted on platforms like Airbnb, and it is the answer to the first question almost every owner asks us.

Two brands dominate this space for short-term rentals: NoiseAware, recently rebranded as Rest, and Minut. Both integrate with the major property management systems, which means the guest text goes out the moment the threshold is crossed, with nobody watching a screen to trigger it.

Standardise the Device Before You Scale It

The most common thing we inherit in a portfolio is a mix of brands. One property on Minut because an owner bought it, two on NoiseAware because a manager set them up, and three with nothing at all. Every one of those has a different dashboard, different threshold logic, and a different alert format.

That is workable at one property and unworkable at twenty. When a portfolio runs one device across every unit, thresholds become a policy rather than a per-property guess, the alerts land in one place, and whoever is on shift recognises what they are looking at instantly. Standardising is worth more than picking the theoretically better brand.

Placement Decides Whether the Data Is Real

A monitor in the wrong spot produces numbers that look fine while the property is genuinely loud. This is the step that gets skipped when a device is installed by whoever happened to be at the property that day.

For an indoor Minut sensor, the manufacturer recommends ceiling placement, centred in the main living area, facing straight down, no higher than about 10 feet, and away from stoves, fireplaces, vents and AC units, all of which distort both noise and smoke readings.

NoiseAware is more specific again. Keep the indoor sensor within about 75 feet of line of sight to the router, at least 10 feet from cordless phones and microwaves, and never behind a couch or a door. That last mistake alone can cost 10 to 20 points on the noise score, which means a genuinely loud night may never trigger an alert at all.

Any property with a pool deck, patio, or other outdoor gathering area needs its own sensor out there. NoiseAware's outdoor unit should sit within 100 to 150 feet of the indoor one, positioned 10 to 20 feet from the activity zone with the microphone facing it directly, and kept clear of pool pumps and AC condensers.

We treat placement the way we treat camera placement, as a documented install step with a photo, not a judgement call made on the day. We laid out that standard in our guide to STR security cameras, and the same discipline applies here.

Thresholds Are a Policy, Not a Setting

For a loud indoor space, a threshold in the 60 to 70 decibel range is a reasonable starting point, and it is worth checking that number against the manufacturer's own guidance before locking it in. Set it too low and you are texting guests who are doing nothing wrong. Set it too high and the first you hear about a problem is from a neighbour.

Across a portfolio, run tighter thresholds overnight than during the day. A busy pool afternoon and a gathering at 1am carry very different risk, and one number cannot serve both. If a newly installed device starts firing false alarms, raise the threshold before you send a single guest message. Few things damage a review faster than being accused of noise you were not making.

What It Costs

Pricing varies by provider and by how many devices a portfolio needs, but a fully integrated setup with automated guest texting typically runs around $15 a month per device. That tends to improve as the property count goes up, and some providers include the hardware at no cost as long as the account stays on an active subscription. If you are running more than a handful of properties, ask about tiered or multi-unit pricing before you accept a single-device rate.

Set against one noise fine, one cancelled stay, or one review that mentions the police, it is among the cheapest lines in the operating budget.

The Part You Cannot Outsource to the Device

This is where most setups fall down. The device sends the first text on its own. Everything after that needs a person.

The sequence our team runs is the same at every property. The first alert triggers a friendly automated text asking the guest to lower the volume. If a second alert lands within 30 minutes of the first, that is no longer a nudge, and someone calls the guest directly instead of sending another message. Every alert is logged with the time, the duration, the peak level, and how it resolved.

That log is the part owners underestimate. When a guest disputes a noise charge, when a neighbour escalates to the city, or when a platform asks what happened, the record either exists or it does not. It is the same principle behind the turnover documentation standard we run on every property. Evidence captured at the time wins the case. Evidence reconstructed afterwards rarely does.

And someone has to be awake. A monitor on a property with nobody on shift after 10pm is an alarm ringing in an empty room. The coverage is the product here, not the sensor.

Smoke Detection Is the Newest Piece

The newer devices can also flag smoke, and Airbnb accepts screenshots from them as proof when a host needs to charge a smoking fee. Right now Minut's on-device AI can distinguish cigarette smoke from marijuana smoke without a camera, and that feature is already live. Rest, formerly NoiseAware, has smoke detection with a track record in the hotel industry, but for short-term rentals specifically it remains waitlist only for now.

Whichever device flags it, the smoking policy and the charge attached to it have to already be written into the house rules or the rental agreement. A detection with no agreed consequence behind it is an argument, not a charge. Get the policy in place first, then let the device do its job.

What We Would Check Across a Portfolio This Week

Which properties have a monitor at all, and whether they are all the same brand. Where each sensor is physically mounted, and whether anything on the manufacturer's exclusion list is sitting next to it. Whether outdoor gathering areas have their own sensor. What the daytime and overnight thresholds are, and whether they were set deliberately or left at a default. Who answers an alert at 1am, and what they are authorised to do. And whether the smoking policy in the house rules matches what the device can now detect.

None of that is expensive. It is the difference between owning a device and running a system. If you want the guest facing side of this tightened up, the wording, the tone, and when to stop texting and call, download the Short-Term Rental Host's Communication Checklist here.

Want help setting up your STR for long-term performance? The team at Corzly manages properties across multiple markets and helps operators build the systems that drive results. Reach out here.