1 / 17

Misura della risposta all’impulso Parametri Acustici temporali e spaziali

Misura della risposta all’impulso Parametri Acustici temporali e spaziali. Informazioni estraibili dalla Risposta Impulsiva. Energia Utile. Energia Dannosa. Alcuni Descrittori Acustici. I parametri acustici (ISO 3382). Tempo di Riverberazione Iniziale (EDT): estrapolato da 0 a -10 dB

bernad
Download Presentation

Misura della risposta all’impulso Parametri Acustici temporali e spaziali

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Misura della risposta all’impulsoParametri Acustici temporali e spaziali Parametri Acustici (ISO 3382)

  2. Informazioni estraibili dalla Risposta Impulsiva Energia Utile Energia Dannosa Parametri Acustici (ISO 3382)

  3. Alcuni Descrittori Acustici Parametri Acustici (ISO 3382)

  4. I parametri acustici (ISO 3382) • Tempo di Riverberazione Iniziale (EDT): estrapolato da 0 a -10 dB • Tempo di riverberazione T10: estrapolato da -5 a -15 dB • Tempo di riverberazione T20: estrapolato da -5 a -25 dB • Tempo di riverberazione T30: estrapolato da -5 a -35 dB Parametri Acustici (ISO 3382)

  5. I parametri acustici (ISO 3382) • Indice di chiarezza C80 (musica sinfonica): • Indice di chiarezza C50 (parlato): Valore ottimale = +/- 1 dB Parametri Acustici (ISO 3382)

  6. I parametri acustici (ISO 3382) • Indice di definizione D: • Tempo baricentrico TS: Parametri Acustici (ISO 3382)

  7. I parametri acustici (ISO 3382) SPL a 10 m • Strenght: • IACC: Parametri Acustici (ISO 3382)

  8. Spatial analysis by directive impulse responses • The initial approach was to use directive microphones for gathering some information about the spatial properties of the sound field “as perceived by the listener” • Two apparently different approaches emerged: binaural dummy heads and pressure-velocity microphones: Binaural microphone (left) and Pressure-velocity microphone (right) Parametri Acustici (ISO 3382)

  9. Microfono Soundfield • The Soundfield microphone allows for simultaneous measurements of the omnidirectional pressure and of the three cartesian components of particle velocity (figure-of-8 patterns) W X Y Z Speech Transmission Index

  10. I parametri acustici (ISO 3382) • Lateral Fraction: • LFC: Parametri Acustici (ISO 3382)

  11. IACC “objective” spatial parameter • It was attempted to “quantify” the “spatiality” of a room by means of “objective” parameters, based on 2-channels impulse responses measured with directive microphones • The most famous “spatial” parameter is IACC (Inter Aural Cross Correlation), based on binaural IR measurements Left pL(t) Right pR(t) 80 ms Parametri Acustici (ISO 3382)

  12. Lateral Fraction (LF) spatial parameter • Another “spatial” parameter is the Lateral Fraction LF • This is defined from a 2-channels impulse response, the first channel is a standard omni microphone, the second channel is a “figure-of-eight” microphone: Omni ho(t) Figure of 8 h8(t) Parametri Acustici (ISO 3382)

  13. Are binaural measurents reproducible? • Experiment performed in anechoic room - same loudspeaker, same source and receiver positions, 5 binaural dummy heads Parametri Acustici (ISO 3382)

  14. Are IACC measurents reproducible? • Diffuse field - huge difference among the 4 dummy heads Parametri Acustici (ISO 3382)

  15. Are LF measurents reproducible? • Experiment performed in the Auditorium of Parma - same loudspeaker, same source and receiver positions, 4 pressure-velocity microphones Parametri Acustici (ISO 3382)

  16. Are LF measurents reproducible? • At 25 m distance, the scatter is really big Parametri Acustici (ISO 3382)

  17. Il plug-in Aurora Acoustical Parameters Parametri Acustici (ISO 3382)

More Related