Noise Interference in Office & Apartment Intercom Systems: How to Fix It


 Camilla Ashdown, 07. 06. 2024 | 5 min read

As old office and apartment intercom systems age, they can develop issues that lead to noise interference and thus disruptions in communication. Let’s explore the common causes of intercom noises, how to avoid them, and a more long-term fix…

intercom systems


No one wants to hear crackling, buzzing, or an echo when they’re trying to communicate with visitors – however, noise interference in intercom systems is an all too prevalent issue in businesses and places of residence. The causes can range from ageing equipment to poor wiring, electromagnetic interference from other devices, and environmental factors such as high humidity.

Although noise interference may seem like a minor annoyance, the more noise issues are left unfixed, the worse problems can become – and in the event of an emergency, miscommunication that results from being unable to hear well could even be a life-threatening issue. Which problems are common, what are the causes, and how can you deal with them in your office or apartment intercom system?

Common Noise Issues & Their Causes

Buzzing or humming noises are often caused by electrical interference, which result from nearby electrical devices or poor grounding within the office or apartment intercom system.  

Static interruptions are commonly caused by radio frequency interference (RFI), which can originate from nearby radio transmissions, wireless devices, or electrical appliances.

Echoes or feedback occur when the audio signal loops back into the microphone, typically due to improper installation or adjustment of the intercom system.

Crackling sounds are one of the most prevalent issues, and the cause is a bit harder to pinpoint - it can occur for various reasons, such as loose connections, corroded wiring, or faulty components.

How to Fix Noise Interference in Your Office or Apartment Intercom System

Clean the Intercom

It seems simple, but dirt and debris can accumulate on the intercom system's surface over time, leading to noise interference. To resolve this, gently clean the intercom with a soft cloth or brush to remove any accumulated dirt - especially in the speaker and microphone area. Avoid harsh chemicals or abrasive cleaners that could damage the system.

Adjust the Volume

Sometimes, high volume settings on indoor stations can cause intercom noise or echo. To address this, adjust the volume on the intercom. If unsure, consult the user manual or contact the manufacturer for guidance.

Check and Tighten the Wiring & Connections

Begin by inspecting all connections within the intercom system, including cables, terminals, and circuit boards. Ensure that all connections are tight and secure to minimize signal loss and interference.

Address Interference

Intercom noise is often caused by interference from other electrical devices. To address this issue:

  • Move the Intercom: If possible, relocate the intercom away from other devices like computers, phones, or printers that emit electromagnetic interference.
  • Alternatively, Move Other Devices: If relocating the intercom isn't feasible, consider moving the interfering devices instead.
  • Improve the Grounding: Improve the grounding of the intercom system to reduce electrical interference. Ensure that the system is properly grounded according to manufacturer specifications and local electrical codes.
  • Shielding and Isolation: Install shielding or isolation devices to protect the intercom system from electromagnetic interference. Use shielded cables and enclosures to minimize the impact of external electromagnetic fields.

Replace Faulty Components

Identify any individual components within the office or apartment intercom system that show signs of wear or damage, such as corroded wiring or malfunctioning circuitry. Many manufacturers sell replacement parts which will allow you to address the issues without having to change the entire device.

Consider a Full Replacement

If none of the above steps work, evaluate the overall efficiency and usefulness of the entire office or apartment intercom system. If your intercom is old, malfunctioning, or is simply not up to modern-day standards, it might be time to invest in a new one. Over time, outdated systems and worn-out parts can lead to more serious issues than only noise interference.

Analogue vs. IP: should you upgrade?

The above issues with noise interference are most common in outdated analogue intercom systems. And, whilst troubleshooting and fixing noises in analog intercom systems can provide temporary relief, upgrading to Voice over Internet Protocol (VoIP) intercom systems offers a long-term solution with enhanced functionality and reliability.

Old intercom systems rely on analog signals transmitted over dedicated wiring, which as discussed often result in limited audio fidelity and grainy video quality. However, with VoIP, these limitations are overcome through digital transmission over IP networks.

VoIP improves audio quality via compression algorithms that optimize voice data for transmission over the Internet. These algorithms help to minimize bandwidth requirements while maintaining high audio clarity, resulting in clearer and more natural-sounding conversations. Additionally, VoIP systems often support wideband audio codecs which offer greater frequency range and richer audio tones: further enhancing the communication experience.

But I have an old building – can you still get IP technology?

There are options available to bring IP intercoms to ‘retrofit’ projects – i.e. old buildings that you cannot, or don’t want to, change the wiring of. You can:

  • Use an IP converter to convert existing 2-wire analog cabling to IP
  • Use the cloud - if you don't have a reliable network, install an LTE intercom at the door and connect it to answering units - which are each connected to the internet via their local network. Or, don't use HW answering units and use intercom calling to the tenants' mobile phones


Dealing with intercom noise can be frustrating, but it is often a solvable issue with some troubleshooting.  By inspecting the wiring, relocating the intercom system, cleaning the device, adjusting the volume, or even replacing it, you can resolve most intercom noise problems. If you're unsure how to proceed, refer to the user manual or reach out to the manufacturer for support. With a bit of patience and persistence, you can achieve clear and uninterrupted communication through your office or apartment intercom system.

And, always remember – if your intercom system is beyond repair or totally outdated, it could be time to upgrade your building's system to an IP intercom solution that offers far more than high-quality sound alone!