Alcons


Alcons

Alcons means Percentage Articulation Loss of Consonants = %ALcons. This machine measure of intelligibility is closely associated with the TEF sound analyzer. It is computed from measurements of the Direct-to-Reverberant Ratio and the Early Decay Time using a set of correlations defined by SynAudCon, and is specified in percent. See also Intelligibility.

Consonants play a much more significant role in speech intelligibility than vowels. If the consonants are heard clearly, the speech can be understood more easily.

Since %ALcons expresses loss of consonant definition, lower values are associated with greater intelligibility. It is generally assumed that the maximum allowable value for typical paging applications is 10%, assuming that the environment is relatively free of masking noise. For learning environments and voice warning systems, the desired value is 5% or less.

Alcons is the measured percentage of Articulation Loss of Consonants by a listener. % Alcons of 0 indicates perfect clarity and intelligibility with no loss of consonant understanding, while 10% and beyond is growing toward bad intelligibility, and 15% typically is the maximum loss acceptable.

The %Alcons method is widely used by acoustical consultants (particularly in the United States), but it has significant drawbacks. First, it is based on measurements in a single one-third octave band centered on 2 kHz; all other frequencies are ignored, so the system’s frequency response must be verified in some other way for the %Alcons score to be meaningful.

Moreover, the method does not account for many factors that can dramatically affect intelligibility, including signal-to-noise ratio, the background noise spectrum, distortion, late reflections or echoes, system frequency response, compression, non-linear phase, equalization and acoustic power. %Alcons measurements of sound systems therefore often yield overly optimistic scores. Where reverberation or strong, late-arriving reflections are the primary problem, however, they can sometimes be more useful and accurate than RASTI.

ee also

*| Speech Transmission Index | STI |

External links

* [http://www.sengpielaudio.com/calculator-ALcons-STI.htm Intelligibility Conversion: Articulation Loss of Consonants (%ALcons) to Speech Transmission Index (STI)]


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • %ALcons — % Alcons es un acrónimo de Percentage Articulation Loss of Consonants (Pérdida porcentual de articulación de las consonantes). Es un valor numérico que se utiliza en acústica para medir las cualidades de una estancia, y cuantifica la… …   Wikipedia Español

  • Alcons — ist das englischsprachige Akronym von Articulation Loss of Consonants, das den Artikulationsverlust für Konsonanten bezeichnet. Der Alcons gibt als Maß des Verständlichkeitsgrades den Anteil in Prozent wieder, wie viele Worte beziehungsweise… …   Deutsch Wikipedia

  • Speech Transmission Index — Speech Transmission Index, short STI is a measure of intelligibility of speech. The understanding of speech, the intelligibility is directly dependent of the background noise level, of the reverberation time, and of the size of the room. For the… …   Wikipedia

  • Sound Transmission Index — Der Speech Transmission Index, kurz auch STI genannt, wird aus der Modulationsübertragungsfunktion berechnet. Es ist ein Messverfahren für den Verständlichkeitsgrad. STI berücksichtigt als einzige Berechnungsmethode den Nachhall, die… …   Deutsch Wikipedia

  • Intelligibility (communication) — Intelligibility is for voice communications, the capability of being understood the quality of language that is comprehensible language or thought.Intelligibility relates to clarity, explicitness, lucidity, comprehensibility, perspicuity,… …   Wikipedia

  • Speech Transmission Index — Le Speech Transmission Index (STI) est une mesure de l intelligibilité de la parole. Sommaire 1 Echelle 2 Voir aussi 3 Références 4 Liens externes …   Wikipédia en Français

  • Audio-Fachbegriffe — A 1/f Rauschen 1/r Gesetz 3:1 Regel Abbildungsbereich Abbildungsbreite A Bewertung Abfallzeit Abhörlautstärke Abhörraum Abhörverstärker Abklingkonstante Abklingzeit AB …   Deutsch Wikipedia

  • Liste der Audio-Fachbegriffe — A 1/f Rauschen 1/r Gesetz 3:1 Regel Abbildungsbereich Abbildungsbreite A Bewertung Abfallzeit Abhörlautstärke Abhörraum Abhörverstärker Abklingkonstante Abklingzeit AB …   Deutsch Wikipedia

  • MOS-Wert — Der Mean Opinion Score (MOS) ist das arithmetische Mittel von einzelnen Bewertungen und kann in einem Bereich von 1 (schlechtester Wert) bis 5 (bester Wert) liegen. In der Telekommunikation wird der MOS Wert vorwiegend zur Beurteilung der… …   Deutsch Wikipedia

  • Speech transmission index — Speech Transmission Index, short STI is a measure of speech transmission quality. The absolute measurement of speech intelligibility is a complex science. The STI measures some physical characteristics of a transmission channel (a room, electro… …   Wikipedia