Describe how the human hearing system works.

Apply appropriate methods and use appropriate metrics to quantify acoustic performance. - Recommend appropriate microphone placement for indoor and outdoor sound measurements. - Define sound transmission loss/sound reduction index. - Describe the standard methods for measuring impact insulation, sound transmission and diffuse-field sound absorption. - Describe how sound insulation measurements are made. - Calculate the sound pressure level in a room due to transmission from an adjacent room using the general insulation equation. - Describe the concept behind the STC rating.

Explain how transducers can be used to measure and produce sound

Predict the transmission, absorption/reflective properties of a material, duct or structure using simple models and/or describe the physical process and factors affecting these phenomena. - Define sound absorption and sound insulation. - Calculate a sound absorption coefficient for a material if the surface impedance is specified for a normal incidence plane wave. - Define rigid and impedance boundary conditions and analyse 1D problems involving such boundary conditions. - Analyse 1D sound propagation in a duct with a sudden change in cross-sectional area. - Describe how a Helmholtz resonator, panel absorber and a reactive muffler work. - Describe the mass law and the assumptions used to derive it. - Describe the coincidence effect and define the coincidence frequency. - Interpret the sound transmission loss spectrum for a double leaf wall system, identifying mass-air-mass resonances, the mass- law region and the coincidence frequency.

Suggest practical methods for reducing or controlling noise. - Describe the sound transmission paths through a double-leaf wall system and methods for increasing sound transmission loss. - Describe how panel stiffness and size affect the transmission loss of a single panel. - Describe what thickness of porous absorber is required to produce maximum sound absorption for normally incident waves.

Identify and use solutions to the 1D and 3D spherically symmetric acoustic wave equation, describe the limitations of these solutions and calculate noise levels for such fields. - Describe the assumptions used in the derivation of the wave equation. - Use the acoustic momentum equation to calculate the acoustic particle velocity of a plane or spherical wave and use this result to calculate sound intensity and sound power. - Define what the “characteristic specific acoustic impedance” of an acoustic medium is. - Calculate amplitude, mean-square and rms values from complex pressure, particle velocity or intensity. - Calculate the sound pressure level, sound intensity level and sound power level produced by a simple source or plane wave. - Describe (in words) the principle of acoustic reciprocity.

Sum coherent and incoherent sound fields and calculate resulting noise levels. - Calculate total sound pressure levels for the addition of incoherent or coherent sounds. - Describe the principles of active noise control.

Analyse the sound field within a room and use measured properties to classify its acoustical performance. - Describe why statistical models (as opposed to an exact solution to the wave equation) are used in room acoustics. - Define Shroeder’s frequency, reverberation time, Sabine room, reverberation room and diffuse field. - Calculate SPL in a reverberant room given SWL and sound absorption (and vice versa). - Calculate sound absorption of a Sabine room given reverberation time and room geometry.

Analyse the sound field produced by simple or directional or distributed sound sources including propagation effects for long distance noise propagation. - Describe (in words) how sound radiates from a simple source. - Define the “acoustic far-field” and describe why radiation from a simple source may be modelled by a plane wave in the acoustic far-field. - Analyse problems where a plane or spherical wave is incident on a rigid plane surface. - Identify when a source may be modelled by a simple source. - Calculate SPL from the SWL and directivity index of a source. - Describe why a baffled speaker is a more efficient radiator of sound than an unbaffled speaker. - Use ISO 9613:2 to calculate outdoor sound levels accounting for excess attenuation due to atmospheric absorption and ground reflections. - Describe how meteorological conditions may affect sound propagation and measured noise levels.