Can You Hear Through Bulletproof Glass?

Bulletproof glass is very thick, which can make it difficult to hear someone speaking on the other side. Fortunately, good communication is achievable without compromising the ballistic integrity of the barrier. Natural sound transfer options and metal voice ports for interior or exterior transaction windows help facilitate clear communication with bulletproof glass.

How to Facilitate Sound Transfer

Maximizing communication with customers is a top priority for ballistic transaction window systems. This is especially true for places such as banks, where patrons would not appreciate having to shout sensitive financial information.

Sound is highly directional, which is why it’s harder to hear someone if they’re facing away from you. If you put a thick pane of bulletproof glass between the speaker and listener, most of the sound waves will bounce right back to the speaker.

In order to facilitate sound transfer, you need to provide clear channels for the sound to bounce through. Using something like the TSS baffle transaction window facilitates sound transfer well because it offers multiple simple paths through the air, so that sound waves can travel from speaker to listener. The baffles ensure that there is no gap in the bulletproofing, so you do not compromise safety.

Baffle Transaction Window

In general, communication will be easier when:

  • There are multiple paths for sound to take, ie the transmission channels are larger
  • The paths are more direct, meaning they bounce less or reflect off fewer surfaces
  • The medium they pass through is as thin as possible or it is a good conductor of sound

Now that you know a little bit more about sound, you’ll have a better understanding of the voice transfer options for bulletproof transaction windows.

How to Ensure Clear Communication through Bulletproof Glass

An additional consideration for transaction windows is visual clarity. Being able to see the person you’re talking to is important for communication, body language, and trust. A clear line of sight can also help personnel on the safe side of the glass identify and keep visual contact with any threats. As a business, you will want to minimize the psychological barriers for your customers. That means designing a ballistic barrier that is unobtrusive and blends into its surroundings.

At TSS, we aim to prioritize aesthetics without compromising safety, and visual obstruction is an important metric when thinking about communication. With that in mind, let’s talk about voice transmission options for transaction windows.

Baffle Transaction Window

This is one of our most popular transaction window options. Large sound channels on either side of the bulletproof window allow sound passage, while baffles ensure that there is no clear shooting lane. This can be used to create a system of multiple transaction windows without metal framing, which is the ballistic barrier option that is the least visually obstructive. Even with a single transaction window, it offers high visual clarity. It is also a more economical product than some of the other options.

Baffle Window 2

Hole and Backer

With this style, a voice channel is cut through the middle of the window (the hole), and an oversized piece of bulletproof glass is placed over the hole on the secure size (the backer). This can be either a small circular hole or a large arch. While the bulletproof material used to create this system is transparent, the small circular version does disrupt visual clarity and offers a smaller channel for sound transfer. A larger arch may be a much better option for visual clarity and sound transfer. These are better suited to interior applications.

Metal Frame Voice Transfer

We offer either the Aluminum Voice Around (AVA) or the Natural Voice Rail (NVR), which are voice transfer passages built into the frame of the bulletproof window. These are similar to the baffle system, with even better visual clarity. Customers may not even notice them.

Metallic Talk-Thru Voice Ports

We offer a variety of talk-thru ports, which are 6” diameter metal transaction speakers. The speaker holes are offset on the threat side and safe side, so sound can travel through but ballistic threats cannot. While these can be disruptive visually, they are small, and often a very good choice for exterior windows. They can also be used for interior bulletproof transaction windows.

TSS_Exterior Transaction Window

Learn more about talk-thru voice ports in our ballistic window voice transmission video.


We don’t usually recommend electronically enhanced sound transfer options, but we do offer them for our bulletproof transaction windows. Occasionally, this will be the right solution for our customers, but they often require tweaking. Issues with crosstalk and static can become barriers to communication, which defeats the purpose. 

Norcon Intercom

Contact TSS to Discover the Best Solution For Your Needs

Each project we work on is unique. Let us know your needs, your goals for your ballistic barrier system, and your aesthetic desires. We can walk you through your options, and make recommendations based on our 20 years of experience designing bulletproof systems.

If you’d like to learn more about voice transmission options for transaction windows, you can view the product specifications here.

For personalized advice about your ballistic barrier needs, don’t hesitate to reach out to TSS. Either call us at (800) 513-1468 or use our online contact form to learn more today!

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