Estimating the precison of the likelihood-ratio output of a forensic-voice-comparison system.
Morrison, G. S., Thirivaran, T., & Epps, J. (2010). Odyssey 2010: The Speaker and Language Recognition Workshop, Brno. [Submitted].

• Matlab Code: CI_calcs 2010-02-16.

Forensic voice comparison and the paradigm shift.
Morrison, G. S. (2009). Science & Justice, 49, 298–308.
doi:10.1016/j.scijus.2009.09.002

Comments on Coulthard & Johnson’s (2007) portrayal of the likelihood-ratio framework.
Morrison, G. S. (2009). Australian Journal of Forensic Sciences, 41, 155–161.
doi:10.1080/00450610903147701

A reponse to the UK position statement on forensic speaker comparison.
Rose, P., & Morrison, G. S. (2009). International Journal of Speech, Language and the Law, 16, 139–163.
doi:10.1558/ijsll.v16i1.139

• pre-publication version

Likelihood-ratio-based forensic speaker comparison using parametric representations of vowel formant trajectories.
Morrison, G. S. (2009). Journal of the Acoustical Society of America, 125, 2387–2397.
doi:10.1121/1.3081384

• 
  

Automatic-type calibration of traditionally derived likelihood ratios: Forensic analysis of Australian English /o/ formant trajectories.
Morrison, G. S., & Kinoshita, Y. (2008). Proceedings of Interspeech 2008 (pp. 1501–1504). International Speech Communication Association.

Forensic speaker recognition of Chinese /i/ and /y/ using likelihood ratios.
Zhang, C., Morrison, G. S., & Rose, P. (2008). Proceedings of Interspeech 2008 (pp. 1937–1940). International Speech Communication Association.

Forensic voice comparison using likelihood ratios based on polynomial curves fitted to the formant trajectories of Australian English /aI/.
Morrison, G. S. (2008). International Journal of Speech, Language and the Law, 15, 249–266.
doi:10.1558/ijsll.v15i2.249

Incorrect versions of Figures 3 and 4 were printed in the paper version. These have been corrected in the online vesion.

I also deal with methodological issues in other papers, but the papers listed in this section have methodology as their primary focus.

If you use my software for research please let me know and give me credit in published papers.

Sound file cutter upper.
Morrison, G. S. (2010). [Software release 2010-01-12].

• Matlab Code: cut_up_soundfiles 2010-01-12.
  
  
• Compiled: cut_up_soundfiles 2010-01-12.
  

train_llr_fusion_robust.m
Morrion, G. S. [Software release 2009-07-02]

Robust version of train_llr_fusion.m from Niko Brümmer’s FoCal Toolbox. This version can handle cases of complete separation.

• Matlab function
  

Analysis of categorical response data: Use logistic regression rather than endpoint-difference scores or discriminant analysis (L).
Morrison, G. S., & Kondaurova, M. V. (2009). Journal of the Acoustical Society of America, 126, 2159–2162.
doi:10.1121/1.3216917

Logistic regression software for speech percepton data.
Morrison, G. S. (2009). [Software release 2009-03-13].

Includes data to run analyses from Morrison & Kondaurova (2009).

• Matlab Code: Logistic Regression Software 2009-03-13
  
  
• Compiled: Logistic Regression Software 2009-03-13
  

FormantMeasurer: Software for efficient human-supervised measurement of formant trajectories.
Morrison, G. S., & Nearey, T. M. (2010). [Software release 2010-01-19].

• Matlab Code: FormantMeasurer 2010-01-19
  
  
• Compiled: FormantMeasurer 2008-01-19
  
  
• Sample sound and marker files: SoundFiles

SoundLabeller: Ergonomically designed software for marking and labelling portions of sound files.
Morrison, G. S. (2010). [Software release 2010-01-15].

• Matlab Code: SoundLabeller 2010-01-15
  
  
• Compiled: SoundLabeller 2010-01-15

Acoustic recording software for speech production experiments.
Morrison, G. S. (2008). [Software release 2008-12-23].

• Matlab Code: AcousticRecording 2008-12-23
  
  
• Compiled: AcousticRecording 2008-12-23
  
  
• Chinese language files (Chinese version of Windows required)
  
  
• An alternative you may also want to try: BAS SpeechRecorder

Matlab function which draws Tippett plots.
Morrison, G. S. (2008). [Software release 2008-11-13].

• Matlab function
  

Matlab implementation of Aitken & Lucy's (2004) forensic likelihood-ratio software using multivariate-kernel-density estimation.
Morrison, G. S. (2007). [Software].

• Matlab function
  
  
• prepublication version of Aitken, C. G. G, & Lucy, D. (2004) Evaluation of trace evidence in the form of multivariate data. Applied Statistics, 54, 109–122.

Comment on “A geometric representation of spectral and temporal vowel features: Quantification of vowel overlap in three linguistic varieties” [J. Acoust Soc. Am. 119, 2334–2350 (2006)] (L).
Morrison, G. S. (2008). Journal of the Acoustical Society of America. 123, 37–40.
doi:10.1121/1.2804633

• prepublication version including footnotes which were removed from the final version because of space constraints
  
  
• Matlab function
  
  
• Matlab function also available at American Institute of Physics Electronic Physics Auxiliary Publication Service (EPAPS): E-JASMAN-123-001801
  
  
• The following article may also be of interest:
  Gorshi, S., Vaseghi, S., & Yan, Q. (2008) Cross-entropic comparison of formants of British, Australian and American English accents. Speech Communication, 50, 564–579. [DOI:10.1016/j.specom.2008.03.013]

Logistic regression modelling for first- and second- language perception data.
Morrison, G. S. (2007). In M. J. Solé, P. Prieto, & J. Mascaró (Eds.), Segmental and prosodic issues in Romance phonology (pp. 219–236). Amsterdam: John Benjamins.

A multinomial logistic regression function is now avaialble in the Matlab Statistics Toolbox. I have provided versions of some of the sample software making use this function. T. M. Nearey’s software allows for more control over the specification of the logistic regression model, in particular it allows one to specify diphone-biassed models. Matlab is required to run the software. Zipped files which include Nearey's software are password protected. Contact me to get the password. See also Logistic regression Software above.

• Logistic regression software to run analysis of hypothetical VOT data: download StatisticsToolbox version
  
  
• Logistic regression software to run analyses of Álvarez González (1980) data: download StatisticsTooblox version
  
  
• Logistic regression software programmed by T. M. Nearey: download
  
  
• Logistic regression software to run analyses of hypothetical VOT data and Álvarez González (1980) data: download Nearey version
  
  
• Logistic regression software to run analyses of Escudero & Boersma (2004) data: download Nearey version
  
  
• Logistic regression software to run analyses of Bion, Escudero, & Morrison (2008) data [not part of the tutorial paper, but provides examples of different (simpler?) drivers for the logistic regression function]: download Nearey version
  

A cross-language vowel normalisation procedure.
Morrison, G. S., & Nearey, T. M. (2006). Canadian Acoustics 34(3), 94–95.
[Proceedings of the Canadian Acoustical Association Conference 2006, Halifax, Nova Scotia, Canada]

• presentation slides
  
  
• Matlab function Release 2008-12-29

An adaptive sampling procedure for speech perception experiments.
Morrison, G. S. (2006). In Proceedings of the Ninth International Conference on Spoken Language Processing: Interspeech 2006 — ICSLP, Pittsburgh, Pennsylvania, USA (pp. 857-860). Bonn, Germany: ISCA.

• poster
  

An appropriate metric for cue weighting in L2 speech perception: Response to Escudero & Boersma (2004).
Morrison, G. S. (2005). Studies in Second Language Acquisition, 27, 597–606.

I also deal with VISC in other papers, but the papers in this section have VISC as a primary focus.

Vowel inherent spectral change.
Morrison, G. S., & Assmann, P. F. (Eds.) (In Prep). Book in preparation for publication by Springer-Verlag, Heidelberg.

chapter outlines

Likelihood-ratio-based forensic speaker comparison using parametric representations of vowel formant trajectories.
Morrison, G. S. (2009). Journal of the Acoustical Society of America, 125, 2387–2397.
doi:10.1121/1.3081384

• 
  
  
• supplementary material

Theories of vowel inherent spectral change: A review.
Morrison, G. S. (2007). Unpublished manuscript.

Testing theories of vowel inherent spectral change.
Morrison, G. S., & Nearey, T. M. (2007). Journal of the Acoustical Society of America, 122, EL15–EL22.
doi:10.1121/1.2739111

• prepublication version with embedded soundfiles and high-quality graphics

L1-Spanish speakers’ acquisition of the English /i/–/I/ contrast II: Perception of vowel inherent spectral change.
Morrison, G. S. (2009). Language & Speech, 52, 437–462.
doi:10.1177/0023830909336583

• abstract
  
  
• 
  
  
• supplementary material

Perception of synthetic vowels by monolingual Canadian-English, Mexican-Spanish, and Peninsular-Spanish listeners.
Morrison, G. S. (2008). Canadian Acoustics, 36(4), 17–23.

L1-Spanish speakers’ acquisition of the English /i/–/I/ contrast: Duration-based perception is not the initial developmental stage.
Morrison, G. S. (2008). Language & Speech, 51, 285–315.
doi:10.1177/0023830908099067

• 
  
  
• supplementary material

Complexity of acoustic-production-based models of speech perception.
Morrison, G. S. (2008). Proceedings of Acoustics’08, (pp. 2369–2374). Paris: Société Française d’Acoustique.

A cross-dialect comparison of Peninsula- and Peruvian-Spanish vowels.
Morrison, G. S., & Escudero, P. (2007). Proceedings of the 16th International Congress of Phonetic Sciences: Saarbrücken 2007.

L1 & L2 production and perception of English and Spanish vowels: A statistical modelling approach.
Morrison, G. S. (2006). Doctoral dissertation, University of Alberta, Edmonton, Alberta, Canada.

Methodological issues in L2 perception research, and vowel spectral cues in Spanish listeners’ perception of word-final /t/ and /d/ in Spanish.
Morrison, G. S. (2006). In M. Diaz-Campos (Ed.), Selected Proceedings of the 2nd Conference on Laboratory Approaches to Spanish Phonetics and Phonology (pp. 35–47). Somerville, MA: Cascadilla Proceedings Project.

Dat is what the PM said: A quantitative analysis of Prime Minister Chrétien’s pronunciation of English voiced dental fricatives.
Morrison, G. S. (2005). Cahiers linguistiques d’Ottawa, 33, 1–21. Ottawa, Ontario: University of Ottawa, Department of Linguistics.

Principles for a quantitative speech learning model.
Morrison, G. S. (2005, November). Poster presented at the Workshop on Models of L1 and L2 Phonetics/Phonology, Utrecht, The Netherlands.

Towards a Quantitative Speech Learning Model.
Morrison, G. S. (2005, May). Poster presented at the 1st ASA Workshop on Second Language Speech Learning, Vancouver, British Columbia, Canada.

An acoustic and statistical analysis of Spanish mid-vowel allophones.
Morrison, G. S. (2004). Estudios de Fonética Experimental, 13, 11–37.

Perception and production of Spanish vowels by English speakers.
Morrison, G. S. (2003). In M. J. Solé, D. Recansens, & J Romero (Eds.), Proceedings of the 15th International Congress of Phonetic Sciences: Barcelona 2003 (pp. 1533–1536). Adelaide, South Australia: Causal Productions.

Spanish listeners’ use of vowel spectral properties as cues to post-vocalic consonant voicing in English.
Morrison, G. S. (2002). In Collected Papers of the First Pan-American/Iberian Meeting on Acoustics [CD-ROM]. Mexico, DF: Mexican Institute of Acoustics.

Effects of L1 duration experience on Japanese and Spanish listeners’ perception of English high front vowels.
Morrison, G. S. (2002). Master’s thesis, Simon Fraser University, Burnaby, British Columbia, Canada.

Perception of English /i/ and /I/ by Japanese & Spanish listeners: Longitudinal results.
Morrison, G. S. (2002). In G. S. Morrison, & L. Zsoldos (Eds.), Proceedings of the North West Linguistics Conference 2002 (pp. 29–48). Burnaby, BC: Simon Fraser University Linguistics Graduate Student Association.

Japanese listeners’ use of duration cues in the identification of English high front vowels.
Morrison, G. S. (2002). In J. Larson, & M. Paster (Eds.), Proceedings of the 28th Annual Meeting of the Berkeley Linguistics Society (pp. 189–200). Berkeley, CA: Berkeley Linguistics Society.

• The thesis and two papers above use discriminant analysis to model perception data, a more appropriate technique would be logistic regression.

Perception of English /i/ and /I/ by Japanese listeners.
Morrison, G. S. (2002). In S. Oh, N. Sawai, K. Shiobara, & R. Wojak (Eds.), University of British Columbia Working Papers in Linguistics Volume 8: Proceedings of NWLC 2001: Northwest Linguistics Conference (pp. 113-131). Vancouver, BC: University of British Columbia, Department of Linguistics. 

[Review of Phonetically based phonology by B. Hayes, R. Kirchner, & D. Steriade (Eds.)].
Morrison, G. S. (2005). Linguist List, 16, 1400.

[Review of The sounds of language: An introduction to phonetics by H. Rogers].
Morrison, G. S. (2001, June). TEAL News, 23-25, 28.

Sounds & Signals: Improving forensic voice comparison. (Poscast report based on an interview with Dr. Geoffrey Stewart Morrison).
Bard, S. (2009, June 19). Science Update. Washington, DC: American Association for the Advancement of Science.

Report begins at time stamp 9:17

Forensic voice comparison – Reality not TV.
Morrison, G. S. (2009, May). 157th Meeting Lay Language Papers, Acoustical Society of America World Wide Press Room.

Teaching the classical Hebrew stem system: The binyanim. 
Morrison, G. S. (1995). Master’s thesis, Vancouver School of Theology, Vancouver, BC, Canada.

I currently have two presentations prepared for invited talks:

Although both talks focus on forensic voice comparison, since this is my area of expertise, the concepts are applicable to many branches of forensic science in which the task is to compare the quantifiable properties of samples of known and questioned origin.

The first talk is aimed at audience members who already have an interest in forensic science, but not necessarily a knowledge of forensic voice comparison or of the likelihood-ratio framework. It is primarily about the philosophy of the likelihood-ratio framework, and is non-technical in that it does not get into the details of how one would calculate a likelihood ratio.

The place of forensic voice comparison in the ongoing paradigm shift

The second talk describes how to calculate forensic likelihood ratios using examples from forensic voice comparison. No previous knowledge of forensic science is assumed. This talk is somewhat more technical than the first, in that it includes a more in-depth conceptual description of the statistics, and examples using data types which will be familiar to people with some knowledge of phonetics; however, it should still be accessible to a general academic audience (don’t be scared by the words ‘statistics’ or ‘phonetics’).

A brief introduction to the evaluation of forensic-voice-comparison evidence

Abridged Curriculum Vitae

University of Alberta, LING 205 Practical Phonetics, Spring 2006

Comporación forense del habla, abril 2010. Especialidad de fonética judicial, Máster en fonética y fonología, Consejo Superior de Investigaciones Científicas / Universidad Internacional Menéndez Pelayo