Acoustics Fundamentals and Measurements with Air-borne Noise Monitoring

This three-day course is intended for engineers and other technical personnel and managers who have a work-related need to understand basic acoustics concepts and how to measure and analyze sound. This is an introductory course and participants need not have any prior knowledge of sound or vibration. Each topic is illustrated by relevant applications, in-class demonstrations, and worked-out numerical examples. Since the practical uses of acoustics principles are vast and diverse, participants are encouraged to confer with the instructor (before, during, and after the course) regarding any work-related concerns.

• How to make proper sound level measurements.
• How to analyze and report acoustic data.
• The basis of decibels (dB) and the A-weighting scale.
• How intensity probes work and allow near-field sound measurements.
• How to measure radiated sound power and sound transmission loss.
• How to use third-octave bands and narrow-band spectrum analyzers.
• How the source-path-receiver approach is used in noise control engineering.
• How sound builds up in enclosures like vehicle interiors and rooms.
• How to monitor and control environmentally offending noise sources

1. Introductory Concepts. Sound in fluids and solids. Sound as particle vibrations. Waveforms and frequency. Sound energy and power consideration. Source-path-receiver model of noise control engineering.
2. Acoustic Waves in Air. Plane and spherical acoustic waves. Spreading loss and plane wave equivalent. Sound pressure, intensity, and power. Decibel (dB) log power scale. Sound reflection and transmission at surfaces. Sound barriers and sound absorptive treatments.
3. Acoustic and Vibration Sensors. Human ear characteristics. Designs and response characteristics of capacitor and electret microphones. Intensity probe design and operational characteristics. Parabolic reflectors use to amplify, localize, and monitor outdoor noise sources. Accelerometers design and frequency response. Non-contacting laser vibrometers.
4. Sound Measurements. Sound level meters. Time weighting (fast, slow, linear). Decibel scales (Linear and A-and C-weightings). Octave band analyzers. Narrow band spectrum analyzers. Critical bands of human hearing. Detecting tones in noise. Microphone calibration techniques.
5. Sound Radiators. Human speech mechanism. Loudspeaker design and response characteristics. Directivity patterns of simple and multi-pole sources: monopole, dipole and quadri-pole sources. Acoustic arrays and beamforming. Sound radiation from vibrating machines and structures. Radiation efficiency. Techniques to control radiated noise.
6. Low Frequency Air Handling Systems. Sound waves in ducts. Fan noise issues and controls. Helmholtz resonators. Quarter-wavelength turners. Muffler designs and their operational performance.
7. In-Air Noise Control and Monitoring. Outdoor sound propagation (e.g. refraction due to temperature and wind) including ground effects. Environmental acoustics (e.g. community noise response, criteria and monitoring procedures). Auditorium and room acoustics (e.g. reverberation criteria and sound absorption). Structural acoustics (e.g. sound transmission loss through single and double panels). Noise control techniques to reduce air-borne and structure-borne sound. Sound exposure level and other environmental noise standards. Topics of interest to the course participants

Dr. Alan D. Stuart, Associate Professor Emeritus of Acoustics, Penn State, has over forty years experience in the field of sound and vibration. He has degrees in mechanical engineering, electrical engineering, and engineering acoustics. For over thirty years he has taught courses on the Fundamentals of Acoustics, Structural Acoustics, Applied Acoustics, Noise Control Engineering, and Sonar Engineering on both the graduate and undergraduate levels as well as at government and industrial organizations throughout the country.

Contact this instructor (please mention course name in the subject line)