free Orban loudness meter app now available

Orban has developed a stand-alone loudness meter for Windows, 
which we are releasing as a free public beta. The meter can be 
downloaded from this link (watch any line wrapping)

http://www.orban.com/meter/setup_Free_Orban_Loudness_Meter
_1.00.exe


Be sure to read the readme file, which is the meter's manual. The 
installer will offer to open the readme as part of the installation 
process.


Here is the press release:


ORBAN INTRODUCES FREE LOUDNESS/LEVEL METERING 
SOFTWARE
 
San Leandro, CA, April 10, 2008 -- Orban today announced that 
the first public beta of Orban Loudness Meter software for 
Windows XP and Vista is now available for free download from 
www.orban.com/meter.
 
This is the first of a family of Orban meters. Future paid versions 
will offer upgraded features including logging, surround 
monitoring, and oversampled peak measurements that accurately 
indicate the peak level of the audio after D/A conversion.
 
This software simultaneously displays instantaneous peaks, VU, 
PPM, CBS Technology Center loudness, and ITU BS.1770 
loudness. All meters include peak-hold functionality that makes 
the peak indications of the meters easy to see.
 
The software accepts two-channel stereo inputs. The VU and PPM 
meters are split to indicate the left and right channels. The PPM 
meter also displays the instantaneous peak values of the L and R 
digital samples.
 
The CBS meter is a"short-term" loudness meter intended to 
display the details of moment-to-moment loudness with dynamics 
similar to a VU meter. It uses the Jones & Torick algorithm 
developed at the CBS Technology Center and published in 1981 in 
the SMPTE Journal.  Created using Orban-developed modeling 
software, the DSP implementation typically matches the original 
analog meter within 0.5 dB on sinewaves, tone bursts and noise. 
 
The Jones & Torick algorithm improves upon the original loudness 
measurement algorithm developed by CBS researchers in the late 
1960s. Its foundation is psychoacoustic studies done at CBS 
Laboratories over a two year period by Torick and the late 
Benjamin Bauer. After surveying existing equal-loudness contour 
curves and finding them inapplicable to measuring the loudness of 
broadcasts, Torick and Bauer organized listening tests that 
resulted in a new set of equal-loudness curves based on octave-
wide noise reproduced by calibrated loudspeakers in a 
semireverberant 16 x 14 x 8 room, which is representative of a room 
in which broadcasts are normally heard. In 1966, they published 
this work in the IEEE Transactions on Audio and Electroacoustics, 
along with results from other tests whose goal was to model the 
loudness integration time constants of human hearing.
 
In 2006, the ITU-R published Recommendation ITU-R BS.1770: 
"Algorithms to measure audio programme loudness and true-peak 
audio level." Developed by G.A. Soulodre, the BS.1770 loudness 
meter uses a frequency-weighted r.m.s. measurement intended to 
be integrated over several seconds -- perhaps as long as an entire 
program segment. As such, it is considered a "long-term" 
loudness measurement because it does not take into account the 
loudness integration time constants of human hearing, as does the 
CBS meter.
 
Orban's BS.1770 loudness meter uses the Leq(RLB2) algorithm as 
specified in the Recommendation. This applies frequency 
weighting before the r.m.s. integrator. The frequency weighting is 
a series connection of pre-filter and RLB weighting curves. The 
Orban meter precisely implements equations (1) and (2) in this 
document by using a rolling integrator whose integration time is 
user-adjustable from one to ten seconds.
 
Additionally, the Orban meter offers an experimental long-term 
loudness indication derived by post-processing the CBS 
algorithm's output. This uses a relatively simple algorithm that 
attempts to mimic a skilled operator's mental integration of the peak 
swings of a meter with "VU-like" dynamics. The operator will 
concentrate most on the highest indications but will tend to ignore 
a single high peak that is atypical of the others.
 
Researchers have long been curious about the Jones & Torick 
meter but been unable to evaluate it and compare it with other 
meters. Orban developed this software because the company 
believed it would be useful to practicing sound engineers and 
researchers and also because Orban is using it in its new Optimod 
8585 Surround Audio Processor. Thanks to this free software, 
engineers and scientists will now have the opportunity to easily 
compare the CBS algorithm with others, including the BS.1770 
Recommendation.
 
The Orban software runs on Windows XP and Vista computers 
having 1.5 GHz or faster Intel Pentium 4 or Intel-compatible 
processors that implement the SSE2 instruction set. While the 
software can be driven by any installed Windows sound device, 
monitoring playback from an application like Windows Media 
Player requires the sound hardware to support Windows Wave 
I/O.


Bob Orban