Lecture

Absorbing Materials: Porous Layers and Panel Absorbers

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In course

EE-548: Audio engineering

This lecture is oriented towards the study of audio engineering, room acoustics, sound propagation, and sound radiation from sources and acoustic antennas. The learning outcomes will be the techniques for microphones and loudspeaker design, as well as room ...

Description

This lecture covers the characteristics and factors affecting the absorption of sound by porous layers and panel absorbers, including optimal density and thickness values, mounting conditions, resonance frequencies, and examples of absorption factors for various materials and setups. It also discusses how the audience and furniture in a room can impact sound absorption and strategies to minimize this effect.

Instructor

Hervé Lissek

Expertise Acoustics and audio engineering, Electroacoustics.Room acoustics.Active noise control.Acoustic metamaterials.Assisted reverberation.Psychoacoustics.Sound spatialization Expertise Acoustics and audio engineering, Electroacoustics.Room acoustics.Active noise control.Acoustic metamaterials.Assisted reverberation.Psychoacoustics.Sound spatialization Mission Head of the Acoustic Group at the Laboratory of Wave Engineering LWE. Research topics :Active Electroacoustic Resonators: turning conventional lou

Official source

Related concepts (25)

Soundproofing

Soundproofing is any means of impeding sound propagation. There are several basic ways to reduce sound: increasing the distance between source and receiver, decoupling, using noise barriers to reflect or absorb the energy of the sound waves, using damping structures such as sound baffles for absorption, or using active antinoise sound generators. Acoustic quieting and noise control can be used to limit unwanted noise.

Absorption (acoustics)

Acoustic absorption refers to the process by which a material, structure, or object takes in sound energy when sound waves are encountered, as opposed to reflecting the energy. Part of the absorbed energy is transformed into heat and part is transmitted through the absorbing body. The energy transformed into heat is said to have been 'lost'. When sound from a loudspeaker collides with the walls of a room part of the sound's energy is reflected, part is transmitted, and part is absorbed into the walls.

Acoustical engineering

Acoustical engineering (also known as acoustic engineering) is the branch of engineering dealing with sound and vibration. It includes the application of acoustics, the science of sound and vibration, in technology. Acoustical engineers are typically concerned with the design, analysis and control of sound. One goal of acoustical engineering can be the reduction of unwanted noise, which is referred to as noise control. Unwanted noise can have significant impacts on animal and human health and well-being, reduce attainment by students in schools, and cause hearing loss.

Room acoustics

Room acoustics is a subfield of acoustics dealing with the behaviour of sound in enclosed or partially-enclosed spaces. The architectural details of a room influences the behaviour of sound waves within it, with the effects varying by frequency. Acoustic reflection, diffraction, and diffusion can combine to create audible phenomena such as room modes and standing waves at specific frequencies and locations, echos, and unique reverberation patterns.

Absorption spectroscopy

Absorption spectroscopy refers to spectroscopic techniques that measure the absorption of electromagnetic radiation, as a function of frequency or wavelength, due to its interaction with a sample. The sample absorbs energy, i.e., photons, from the radiating field. The intensity of the absorption varies as a function of frequency, and this variation is the absorption spectrum. Absorption spectroscopy is performed across the electromagnetic spectrum.

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