The director of the Noise and Vibrations Laboratory, Dr. Koorosh Naghshineh, teaches multiple classes in the areas of noise control and vibration. One of these classes, Engineering Noise Control, has a lab section that is taught in the NVL. Using the equipment available, students learn about the fundamentals of noise, how to measure various acoustic properties, and how to interpret different characteristics of noise. Below are examples of what types of experiments are run for teaching purposes.
Acoustic transmission tube fitted with side branch resonators
In this lab, two different types of resonators, a quarter-wave resonator and a Helmholtz resonator, are used to study how resonators can attenuate noise. An experimental setup (shown below) was created using a transmission tube connected to a speaker at one end and left open on the other. This tube is fitted with each resonator and the sound pressure at the open tube is measured using the Sound Level Meter. Each resonator can be modified in length by moving the plunger up and down. Using principles taught in class, students study how to design a resonator cavity length such that the noise being emitted from the speaker is significantly attenuated. Resonators are used in various industries because of this ability to attenuate unwanted noise.
Acoustic modes of an enclosure