Subject: Re: Objective intelligibility measurements From: Elena Grassi <elena.grassi@xxxxxxxx> Date: Mon, 15 Sep 2008 08:02:09 -0400 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>Matt, have you considered the STMI out of Shihab Shamma's lab? It accounts for both spetral and temporal characteristics. You can take a look at: Chi et al, J. Acoust. Soc. Am. 106(5) 2719, 1999. Elhilali et al, Speech Communication 41(2003) 331-348. Chi et al, J. Acoust. Soc. Am. 118(2), 2005. Hope it helps -elena On Mon, Sep 15, 2008 at 5:25 AM, Matthew Reynolds <matthew.reynolds@xxxxxxxx> wrote: > Hi all, > > I am in need of a bit of advice regarding objective measures of > intelligibility such as the AI and the STI. I am interested in assessing > comparative intelligibility of 2 communication systems in noise with regard > to their frequency spectra, however the systems in question use vocoder type > codecs to transmit/recreate the speech, introducing non linear distortion > that the above mentioned methods do not account for. However, my proposal is > this; my signal path in both systems involves CELP algorithms and therefore > a direct comparison using AI or STI to assess the intelligibility is not > valid, however, it should be possible to gain a score for each system with > no additive noise, then repeat the tests with additive noise in the acoustic > interface (i.e. in the room with the loudspeaker, so not passing through the > electronic signal path, algorithms etc) and see which system 'survives' the > noise better with respect to its AI/STI score. This seems to be a valid > approach in gaining an idea as to which system will perform better in > acoustic noise, although obviously will not produce 'absolute' results for > each system. > > Ideally I'd like to do this with AI as it involves measuring signal to noise > ratios in 1/3 octave bands, something which I can readily do, whereas to > implement an STI measurement will require purchasing some (probably > expensive) software. > > > Thanks in advance for your help > Matt Reynolds >