Measuring Noise Pollution
Through investigating the nature, sources and level of noise produced in their environment, students are introduced to the concept of noise pollution. They learn about the undesirable and disturbing effects of noise and the resulting consequences on people's health, as well as on the health of the environment. They use a sound level meter that consists of a sound sensor attached to the LEGO® EV3 Intelligent Brick to record the noise level emitted by various sources. They are introduced to engineering concepts such as sensors, decibel (dB) measurements, and sound pressure used to measure the noise level. Students are introduced to impairments resulting from noise exposure such as speech interference, hearing loss, sleep disruption and reduced productivity. They identify potential noise pollution sources, and based on recorded data, they classify these sources into levels of annoyance. Students also explore the technologies designed by engineers to protect against the harmful effects of noise pollution.
Students measure noise pollution by constructing and using a sound level meter.Copyright 2012 Violet Mwaffo, Polytechnic Institute of NYU
Engineers must evaluate a number of quality factors, such as the level of noise produced, while designing new technologies and devices. For some products, noise level reduction is a main concern in the engineering design process. In designing products from transportation vehicles such as aircraft, cars and trains, to household appliances such as refrigerators and air conditioners, engineers strive to reduce the level of harmful noise in order to comply with official safety requirements. To help determine if their products meet these noise level safety requirements, engineers design tools to measure noise levels. Engineers also design appliances to protect against loud sounds such as ear plugs and noise-cancelling headphones, noise reduction windows and doors, and noise reduction materials such as mineral fiber, acoustical foam, glass fiber and ceramic fiber.
During this activity, students construct noise level meters, which is an example of a combination mechanical and electrical engineering project that uses a sensor to convert a physical quantity into an electric signal that is read and interpreted by a computer (the LEGO brick). The activity also presents connections to computer science through the recording program and use of mathematics to produce the results of the measurements and a noise level graphical representation display. By recording and plotting data, students increase their understanding of graphical data displays and how engineers analyze data to solve real-world design challenges.
After this activity, students should be able to:
- Explain noise pollution and how engineers measure it.
- Describe and list examples of impairments resulting from noise pollution.
- Describe and list solutions proposed by engineers to protect against unwanted noise.
- Construct a noise level meter to record noise pollution in the classroom.
- Plot and analyze data.