Loudness monitoring of programme levels is needed in

radio Radio is the technology of communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connec ...

and

television Television (TV) is a telecommunication medium for transmitting moving images and sound. Additionally, the term can refer to a physical television set rather than the medium of transmission. Television is a mass medium for advertising, ...

broadcasting Broadcasting is the data distribution, distribution of sound, audio audiovisual content to dispersed audiences via a electronic medium (communication), mass communications medium, typically one using the electromagnetic spectrum (radio waves), ...

, as well as in audio post production. Traditional methods of measuring signal levels, such as the

peak programme meter A peak programme meter (PPM) is an instrument used in professional audio that indicates the level of an audio signal. Different kinds of PPM fall into broad categories: *True peak programme meter. This shows the peak level of the waveform n ...

and

VU meter A volume unit (VU) meter or standard volume indicator (SVI) is a device displaying a representation of the Signal-to-noise ratio, signal level in audio equipment. The original design was proposed in the 1940 Institute of Radio Engineers, IRE pap ...

, do not give the subjectively valid measure of

loudness In acoustics, loudness is the subjectivity, subjective perception of sound pressure. More formally, it is defined as the "attribute of auditory sensation in terms of which sounds can be ordered on a scale extending from quiet to loud". The relat ...

that many would argue is needed to optimise the listening experience when changing channels or swapping disks. The need for proper loudness monitoring is apparent in the loudness war that is now found everywhere in the audio field, and the extreme compression that is now applied to programme levels.

Loudness meters

Meters have been introduced that aim to measure the human perceived loudness by taking account of the

equal-loudness contours An equal-loudness contour is a measure of sound pressure level, over the frequency spectrum, for which a listener perceives a constant loudness when presented with pure steady tones. The unit of measurement for loudness levels is the phon and ...

and other factors, such as audio spectrum, duration, compression and intensity. One such device was developed by

CBS Laboratories CBS Laboratories or CBS Labs (later known as the CBS Technology Center or CTC) was the technology research and development organization of the CBS television network. Innovations developed at the labs included many groundbreaking broadcast, industr ...

in the 1980s. Complaints to broadcasters about the intrusive level of interstitials programs (advertisements, commercials) has resulted in projects to develop such meters. Based on loudness metering, many manufacturers have developed real-time audio processors that adjust the audio signal to match a specified target loudness level that preserves volume consistency at home listeners.

EBU Mode meters

In August 2010, the

European Broadcasting Union The European Broadcasting Union (EBU; , UER) is an alliance of Public broadcasting, public service media organisations in countries within the European Broadcasting Area (EBA) or who are member states of the Council of Europe, members of the ...

published a new metering specificatio
EBU Tech 3341
which builds on ITU-R BS.1770. To make sure meters from different manufacturers provide the same reading in LUFS units, EBU Tech 3341 specifies the ''EBU Mode'', which includes a Momentary (400ms), Short term (3s) and Integrated (from start to stop) meter and a set of audio signals to test the meters.EBU Tech 3341 Loudness Metering: ‘EBU Mode’ metering to supplement loudness normalisation in accordance with EBU R 128
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References

External links

EBU Tech 3341 audio test signalsITU-R BS.1770: Algorithms to measure audio programme loudness and true-peak audio levelEBU publishes loudness test material
* {{DEFAULTSORT:Loudness Monitoring Audio engineering Broadcast engineering Sound production technology Sound recording

Loudness meters

EBU Mode meters

See also

References

External links