Noise Attenuating Blocks

Solving the Problem of Low Frequency Noise Pollution

Associate Professor Lee Heow Pueh from NUS Mechanical Engineering and his team has designed a set of noise attenuating blocks that are capable of cancelling low frequency noise below 500 Hertz by an average of 31 decibels. This is six times more effective than commonly used noise barriers.

Its modular design makes the barrier lighter and thinner than current commercially available devices. In addition, each 3D-printed block can be customised to cancel a specific noise frequency by adjusting the size of the air cavity and the neck opening within the block. The blocks can then be slotted into a grid-like host structure to function as a noise barrier.

Complementary to this development, the team also developed a mobile application capable of accurately tracking noise data based on a new method of calibrating the microphones of smartphones called “Noise Explorer”. Noise Explorer can measure sound pressure levels and frequencies with an accuracy of less than one decibel for 99.7 percent of measurements in the team’s experiments.

An immediate application of Noise Explorer is for crowdsourcing noise data to help authorities identify

The researchers were able to control the properties of the noise barrier and produce them affordably. and mitigate the source of noise more effectively. Other potential uses include tracking one’s exposure to noise over a period of time and coupling with artificial intelligence for condition monitoring of devices and equipment.

The work of Assoc Prof Lee and his team was published in the journal “Acoustics” in April 2019. The team is currently exploring further development and commercialisation of their noise attenuating blocks as well as improving the aesthetics of the blocks such that they can be seamlessly integrated into a building’s architectural design.

Assoc Prof Lee Heow Pueh from NUS Mechanical Engineering (left) holding up the noise attenuating block that his research team has invented.