slide1 l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Past, Present and Future of STI Herman J. M. Steeneken (www.steeneken.com) PowerPoint Presentation
Download Presentation
Past, Present and Future of STI Herman J. M. Steeneken (www.steeneken.com)

Loading in 2 Seconds...

play fullscreen
1 / 34

Past, Present and Future of STI Herman J. M. Steeneken (www.steeneken.com) - PowerPoint PPT Presentation


  • 106 Views
  • Uploaded on

Past, Present and Future of STI Herman J. M. Steeneken (www.steeneken.com).

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Past, Present and Future of STI Herman J. M. Steeneken (www.steeneken.com)' - ponce


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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

Past, Present and Future of STI

Herman J. M. Steeneken (www.steeneken.com)

Ecophon Seminar, Sept. 2006

slide2

Past: STI (1971, 1980), Envelope Spectrum (1972), MTF (1975), RASTI (1979), prediction by ray-tracing(1981), IEC 60268-16 (1988, 1998)Present: Revised STI (1992, 1999, 2002), STIPA (2001), IEC 60268-16 (2003), ISO 9921 (2003)New and Future: Binaural STI, improvement measurement STI from speech signal, non-native speech, vocoders

Ecophon Seminar, Sept. 2006

signal to noise ratio
Signal-to-Noise ratio !!!

Ecophon Seminar, Sept. 2006

assessment methods
Assessment Methods
  • Subjective assessment with subjects (speakers and listeners): representative, limited reproduction, no diagnostics, laborious
  • Objective assessment based on physical properties (measurements): reproducible, diagnostic, fast
  • Objective methods allow prediction of system performance: design tool

Ecophon Seminar, Sept. 2006

speech and noise
Speech and Noise

Ecophon Seminar, Sept. 2006

spatial line frequency equivalent to mtf
Spatial line frequency equivalent to MTF

Ecophon Seminar, Sept. 2006

distortion of speech envelope
Distortion of Speech Envelope

Ecophon Seminar, Sept. 2006

dynamic measurement of snr
Dynamic measurement of SNR

Ecophon Seminar, Sept. 2006

matrix for seven mtf s
Matrix for seven MTF’s

1 Hz

3 Hz

10 Hz

X

Ecophon Seminar, Sept. 2006

calculation of sti
CALCULATION of STI

Ecophon Seminar, Sept. 2006

calculation scheme
Calculation scheme

Ecophon Seminar, Sept. 2006

frequency weightings various studies
Frequency weightings (various studies)

Ecophon Seminar, Sept. 2006

redundancy with image detection
Redundancy with image detection

Ecophon Seminar, Sept. 2006

frequency weightings cvc words
Frequency weightings (CVC words)

Ecophon Seminar, Sept. 2006

relation noise and band pass limiting
Relation Noise and Band-pass limiting

S.d.= 4.4%

Male speech

Ecophon Seminar, Sept. 2006

listening test with four subjects
Listening test with four subjects

Ecophon Seminar, Sept. 2006

slide18

Embedded CVC words:

versta des over

en nu fijs uit

het woord zek einde

noteer lal punt

“Semi random” combination

of:

17 initial consonants

15 vowels

11 final consonants

Ecophon Seminar, Sept. 2006

relation agc and echoes
Relation AGC and echoes

S.d.= 6.9 %

Male speech

Ecophon Seminar, Sept. 2006

qualification of sti acustica 1984
Qualification of STI (Acustica, 1984)

Ecophon Seminar, Sept. 2006

performance cabin public address
Performance cabin public address

Ecophon Seminar, Sept. 2006

iso sti contours
Iso-STI contours

Ecophon Seminar, Sept. 2006

effective gain of a pa system
Effective gain of a PA-system

Ecophon Seminar, Sept. 2006

field measurement
Field measurement

Ecophon Seminar, Sept. 2006

full sti sti 14 and limited modulation frequency range sti 3
Full STI (STI-14 and limited modulation frequency range STI-3)
  • STI-14
  • Seven octave bands
  • 14 Modulation frequencies
  • Random envelope for octaves
  • not under test
  • STI-3
  • Seven octaves
  • 3 Modulation frequencies
  • (1.0, 3.15, and 10 Hz)
  • Random envelope for octaves
  • not under test

Ecophon Seminar, Sept. 2006

rasti room acoustics sti 1979
RASTI (Room Acoustics STI,1979)

Only for person-to-person

communication assessment

Two octave bands

(500Hz and 2 kHz)

Complex envelope

(4 and 5 mod. freq.)

see Acustica 1984, IEC 60268-16

Ecophon Seminar, Sept. 2006

sti pa sti public address 2001
STI-PA (STI Public Address, 2001)

Assessment of Public Address

including: acoustic environment,

band-pass limiting, overload dis-

tortion

Seven octave bands

(125 Hz and 250 Hz merged)

Complex envelope

(2 simultaneous modulation

frequencies per band)

see IEC 60268-16

Ecophon Seminar, Sept. 2006

future
Future
  • Binaural STI
  • Improvement using Speech as test signal
  • Non-native talkers and listeners

Ecophon Seminar, Sept. 2006

future binaural sti i
Future: Binaural STI (I)

Use artificial head and perform simultaneous measurement on both ears

Select highest performance (best ear selection)

Use cross correlation approach for 500, 1000, and 2000 Hz.

Ecophon Seminar, Sept. 2006

future binaural sti ii
Future: Binaural STI (II)

Ecophon Seminar, Sept. 2006

future n on native talkers and listeners
Future: non-native talkers and listeners

Ecophon Seminar, Sept. 2006

conclusions
Conclusions
  • STI predicts the speech intelligibility for many types of distortion: noise, band-pass limiting, non-linearity's, temporal, vocoding, non-native speech, and binaural hearing.
  • Improvements (measuring methods or scope) of STI will not change the qualification ranges.
  • STI is an international standardized method (ISO9921, IEC 60268-16) and used for many national standards.

Ecophon Seminar, Sept. 2006

questions
Questions?

Ecophon Seminar, Sept. 2006