User`s manual

LM6 - Radar Loudness Meter / 21
EN
Display
LM6/LM2mayuseeitherthemeasurementunitofLU(LoudnessUnits)orLUFS
(LoudnessUnitsFullScale).LUandLUFSaremeasurementsindB,reflectingthe
estimatedgainoffsettoarriveatacertainReferenceLoudness(LU)orMaximum
Loudness(LUFS)asdefinedinBS.1770.SinceacommonreferencepointforLUhas
notbeenagreedonatthetimeofwriting,LUFS(or“LKFS”,pointingspecificallyto
theLeq(R2LB)weightingofBS.1770),mightbefavoredinitiallytoavoidambiguous
use of the term LU.
The effectiveness of any loudness meter depends on both the graphical appearance
and dynamic behavior of its display, as well as on its underlying measurement
algorithms. A short-term loudness meter also relies on the measurement algorithm’s
ability to output pertinent loudness information using different analysis windows,
for instance, 200-800 ms for running realtime updates. It should be noted how
theoptimumsizeofthiswindowvariesfromstudytostudy,possiblybecausethe
objectiveofarunningdisplayhasn’tbeenfullyagreedupon.
Formalevaluationofavisualizationsystemischallenging:Firstofall,oneor
more metrics must be defined by which the display should be evaluated. The
correspondence between the sound heard and the picture seen is one aspect to be
evaluated.Anothermetriccouldcharacterizethespeedofreadingthemeterreliably.
InTCElectronicLM2,LM5andLM6,short-term,mid-termandlong-termofloudness
measurementsaretiedtogethercoherently,anddisplayedinnovelways(angular
readingandradar)thatwerepreferredinitsdevelopmentandtestphases.However,
weremainopentosuggestionsforfurtherimprovementofthevisualizationof
loudness.