Lecture

Auditory Masking: Simultaneous and Temporal Effects

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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 concept of auditory masking, where a sound can render another inaudible due to the ear's behavior. Different types of masking, such as simultaneous, backward, and forward masking, are explained. The lecture also delves into how masking affects the loudness and pitch of sounds, allowing for sound compression. Additionally, the discussion extends to temporal masking, where sounds can mask each other even if not simultaneous, exploring forward and backward masking effects. Critical bands, which influence perception alteration of tones, and cochlear filter banks are also discussed, shedding light on how the auditory system behaves as a filter bank with overlapping bands.

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 (31)

Data compression

In information theory, data compression, source coding, or bit-rate reduction is the process of encoding information using fewer bits than the original representation. Any particular compression is either lossy or lossless. Lossless compression reduces bits by identifying and eliminating statistical redundancy. No information is lost in lossless compression. Lossy compression reduces bits by removing unnecessary or less important information.

Lossless compression

Lossless compression is a class of data compression that allows the original data to be perfectly reconstructed from the compressed data with no loss of information. Lossless compression is possible because most real-world data exhibits statistical redundancy. By contrast, lossy compression permits reconstruction only of an approximation of the original data, though usually with greatly improved compression rates (and therefore reduced media sizes).

Lossy compression

In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data size for storing, handling, and transmitting content. The different versions of the photo of the cat on this page show how higher degrees of approximation create coarser images as more details are removed. This is opposed to lossless data compression (reversible data compression) which does not degrade the data.

Sound

In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the reception of such waves and their perception by the brain. Only acoustic waves that have frequencies lying between about 20 Hz and 20 kHz, the audio frequency range, elicit an auditory percept in humans. In air at atmospheric pressure, these represent sound waves with wavelengths of to . Sound waves above 20 kHz are known as ultrasound and are not audible to humans.

Compression artifact

A compression artifact (or artefact) is a noticeable distortion of media (including , audio, and video) caused by the application of lossy compression. Lossy data compression involves discarding some of the media's data so that it becomes small enough to be stored within the desired or transmitted (streamed) within the available bandwidth (known as the data rate or bit rate). If the compressor cannot store enough data in the compressed version, the result is a loss of quality, or introduction of artifacts.

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