How often have you stood in an underground station, suitcase in hand, only to strain to understand an indecipherable announcement over the tannoy?
More than just high-quality speakers, modern public spaces require sophisticated acoustic systems that balance sound reinforcement with noise control.
In Australia’s busiest transport hubs, background noise — from running trains to rumbling crowds — makes clear communication a challenge. That’s where acoustic engineering comes in: designing systems that cut through the noise and ensure every announcement reaches commuters with clarity.
Engineering acoustic systems for public announcements
Public address systems in transit environments need to do more than amplify sound. They require carefully engineered acoustic systems that balance reinforcement with noise control. Engineers prioritise passive treatments such as sound-absorbing materials and spatial design to minimise reverberation and improve announcement clarity.
Controlling sound reflection is hugely helpful. To direct how sound bounces around a space, acoustic engineers use acoustic design principles and consider materials, shapes, and spatial arrangements. Surfaces may be chosen for their sound-absorbing properties to reduce unwanted echoes that can blur announcements.
The Australian Acoustical Society (AAS) publishes guidelines on material selection and acoustic treatment, which inform these design choices.
High-quality speakers, strategically placed to cover all areas of a station, work alongside digital signal processors. The latter maintain consistent audio quality across the network, while operators manually adjust announcements during incidents or emergencies.
Applying acoustic principles across Australian networks
Australian cities have been proactive in applying these acoustic engineering principles in their public transport networks. In Sydney and Melbourne, the design of metro stations incorporates both architectural and electronic solutions to address noise challenges.
Australian networks beyond Sydney and Melbourne show similar innovation. Brisbane Metro vehicles incorporate safety and accessibility features such as Acoustic Vehicle Alerting Systems and onboard hearing loops to improve announcement audibility for all passengers.
At Springfield Central station in Queensland, an audio induction loop interfaces directly with commuters’ hearing aids, ensuring clear announcements despite platform noise.
Queensland Rail also implements trackside noise mitigation — such as absorptive barriers and environmental noise planning thresholds under the state’s Environmental Protection Act — to balance safety with community amenity.
Smart systems and digital upgrades
Modern station designs often include acoustic panels and sound barriers that help focus the public address system’s output toward waiting areas and platforms. Melbourne’s Metro Tunnel project, among others, has addressed station acoustics through material selection and facility design, though specific solutions vary by site.
Additionally, real-time sound management systems are integrated with the station’s overall communication networks. These systems are constantly monitored and adjusted using feedback from environmental sensors. This approach helps manage unexpected spikes in noise, such as during rush hours or special events.
In a recent project for Sydney Trains, engineers successfully installed a large-scale Dante network to streamline communications across the rail network. This advanced digital audio system allows multiple channels of high-quality audio to be routed seamlessly between devices over standard network cables. The IP-based Dante system simplifies audio routing across vast networks, thus leveraging existing digital infrastructure to maintain signal integrity.
The Dante system’s capability to handle vast amounts of audio data in real time has proved especially beneficial in environments where clarity is paramount. In Sydney Trains’ rail network, it ensures that announcements, safety messages, and background music are delivered crisply and without interference, even in the face of heavy ambient noise.
While Sydney Trains currently stands as the primary example of Dante deployment in Australia’s transport networks, internationally, Dante is also utilised in major infrastructure projects such as Istanbul Airport.
Thanks to acoustic engineers, you’ll spend a lot less time wandering train stations, baffled by mumbling tannoy calls. With smarter networks cutting echoes and balancing audio levels, you can rely on crisp, clear announcements, even when the crowds and trains crank up the volume.
Engineering is everywhere
Engineering shapes our world, influencing every aspect of our lives: housing, transport, food and drink, technology and communication, art and entertainment, the news media, health, education, finance, and more. Follow this blog series as we continue to explore!
