Fundamentals of acoustics and noise control

• describe and apply fundamental acoustic concepts such as the sound pressure, the particle velocity, the speed of sound, the characteristic impedance of the medium
• describe and interpret plane sound fields, including standing waves
• describe and interpret the sound field generated by monopoles and dipoles
• describe the fundamental properties of transducers
• calculate sound transmission between two fluids
• explain the effect of a reflecting plane
• explain how sound is measured, describe the decibel scale, A-weighted levels, and octave and one-third octave bands
• explain the usefulness of the concept of sound power and describe how this quantity is used
• describe and interpret resonances and modes in rooms
• describe and interpret acoustic energy balance considerations in a room
• describe fundamental properties of our hearing, hearing threshold, masking
• calculate sound transmission through simple constructions

Fundamental acoustic concepts and measuring units. Human hearing and speech. Measurement and evaluation of sound, A-weighting, time constants and equivalent sound pressure level. Octave and one-third octave band analyses of noise. Addition of noise from uncorrelated sound sources. The use of complex notation. Energy density, sound intensity and sound power. Impedance concepts. Plane and spherical sound waves, interference fields. Reflection and transmission of sound. Sound radiation from monopole and dipole sources, sound radiation from a piston in a baffle. Normal modes in a rectangular room. The diffuse sound field, the energy balance equation in a room and the reverberation time. Sound absorbing materials. Natural modes and resonances in simple mechanical and acoustic systems. Structure-borne sound, vibration isolation of machinery. Sound insulation of single and double constructions. Elektrodynamic loudspeakers

01005/01007, Advanced engineering mathematics 1/Linear and differentiable mathematical models (or equivalent)

Lectures, problem solving and compulsory hand-ins (problem sets and laboratory exercise report).

This course is a prerequisite for all advanced courses on acoustics.

E-learning anvendes i form af podcast lectures, talks (TED talks) and web-based tools.