Category Archives: Uncategorized

These are for all my other posts, like introductions

Confirming authorship on papers

Recently, I was working on a paper where we all made mistakes regarding authorship. We withdraw the paper in question before publication, and we have all been writing new guidelines for our labs in order to prevent similar mistakes in the future.

Our new guidelines require that active authors on a paper ensure that everyone who has touched any of the data or intellectual contributions on the paper read and respond to the email message below. Responses are then stored on the authors’ computers to document who does and does not wish to be an author.

(We will have later blog post on authorship order – those policies are currently being rewritten.)

Progress on the paper does not occur until all are in agreement on authorship AND authorship order:

Dear {name}, potential author on {article/project}

A paper on the above topic is currently in preparation. You are receiving this email because you may have had some contact with some aspect of this project.

According to what is sometimes called the Vancouver Convention, there are four key components to justify authorship on a given poster, proceedings paper, journal article, or project:

1)         Substantial contributions* to the conception or design of the work, or the acquisition, analysis, or interpretation of data for the work; AND 

2)         Drafting the work or revising it critically for important intellectual content; AND 

3)         Final approval of the version to be published; AND 

4)         Agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. 

*we consider the term “substantial contributions” here to be equivalent to “substantive intellectual contributions” as described in the Vancouver Convention protocols as well as to “substantial professional contributions” as described in section 8.12 of the “Ethical Principles of Psychologists and Code of Conduct” of the American Psychological Association:

Details on the Vancouver Convention protocols can be found in this website of the international committee of medical journal editors:

All those designated as authors should meet all four criteria for authorship, and all who meet the four criteria should be identified as authors.  Those who meet some but not all four criteria should be acknowledged.

In view of the above considerations, we are asking you as an individual for a statement of your contributions relative to the four points above.

Referring to the above points, please answer the following questions regarding your own contributions:

1)         Do you consider your contributions to satisfy the requirement of “substantial contributions” as described above? If so, please describe your contributions here:

2)         Have you or will you contribute to drafting the work or revising it critically for important intellectual content (yes or no)? If so, please describe:

3)         Have you or will you commit to providing final approval of the version to be published? (Yes or No): 

4)         Do you agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved (Yes or No)?: 

Phonological conditioning of affricate variability in Emirati Arabic

Today, Marta Szreder (first author) and I published an article on Phonological conditioning of affricate variability in Emirati Arabic. The article studies the [k∼tʃ] and [dʒ∼j] alternations in Emirati Arabic. In the article, we show that coronal obstruents [t,d] and coronal postalveolar fricatives [ʃ] inhibit production of the fricative variant of [dʒ] in the [dʒ∼j] alternation, but not the fricative variant of [k] in the [k∼tʃ] alternation, as seen in Figure 5 from the paper (below). The results suggest the [k∼tʃ] alternation is a completed phonemic change, while the [dʒ∼j] alternation is a an ongoing process.

Figure 5: Interaction graph showing relative affrication in /k/ and /dʒ/ phonemes based on whether there was a /t,d,ʃ/ within one vowel, somewhere further away in the word, or completely absent from the word.

The full abstract is quoted below:

This study investigates the conditioning effects of neighbouring consonants on the realisation of the phonemes /k/ and /dʒ/ in Emirati Arabic (EA), which are optionally realised as [tʃ] and [j], respectively. Based on previous accounts of EA and other Gulf Arabic (GA) dialects, we set out to test the prediction that proximity of other, phonetically similar coronal (COR) obstruents [COR, −son, −cont] and coronal postalveolar fricatives [COR, −ant] inhibit the surface realisation of the affricate variants of these phonemes. We examine elicitation data from twenty young female native speakers of EA, using stimuli with the target segment in the presence of a similar neighbour, as compared to words with the neighbour at a longer distance or with another coronal consonant. The results point to an asymmetry in the behaviour of the voiced and voiceless targets, such that the predicted inhibitory effect is confirmed for the voiced, but not the voiceless target. We argue that this finding, coupled with a consideration of the intra-participant and lexical trends in the data, is compatible with an approach that treats the two processes as being at different stages of development, where the [k∼tʃ] alternation is a completed phonemic change, while the [dʒ∼j] alternation is a synchronic phonological process.

Szreder, Marta & Derrick, Donald (2023) Phonological conditioning of affricate variability in Emirati Arabic, Journal of the International Phonetic Association. 1-19.

Red Wolf: My new video game

Red Wolf

My first commercial video game is now available on the Android Google Play Store, and you can see an advertisement on my YouTube Channel. This game is inspired by the fairy-tale of Little Red Riding Hood. It revises the story through the eyes of a farmer named Crimson who is trying to protect his cows, sheep, and chicken.

Will Crimson hear the call to protect his animals?

Will he rush foolishly into battle, ignore the plight of his animals and go back to sleep, or visit the local town of Wolfville?

There are 27 endings to this game, and upon completion, you can replay the game to see each of the memorials to Crimson’s possible lives in the cemetery of the possible.

Colorized Schlieren – with and without face masks

This is my first professional (as opposed to personal) youtube video, on my work channel for Maps of Speech. Today I’m making my debut with a scientific report on colorized schlieren images of speech air flow with and without masks. Please share widely, and encourage others to share widely. This is intended to be a worldwide release, and has been approved by the New Zealand Ministry of Business, Innovation, and Employment’s communications team, as well as our COVID-research team. In general, videos on this channel are more formal than my HoT videos, and will often be made in collaboration with whatever research team is working on the related projects. The details below this video link to three other unlisted videos that show the entirety of the schlieren videos referenced – without any audio commentary.

Frame of Colorized Schlieren data from a speaker saying “The beige hues on the waters of the loch impressed all”, no face mask.

The Impacts of a Community-Based Health Education and Nutritional Support Program on Birth Outcomes Among Migrant Workers in Maesot, Thailand: A Retrospective Review

Used by permission: Charis Project / Shade Tree Foundation.

Wayland Joseph Blue, myself, and Carrien Leith Blue have co-authored a paper on the benefits of community-based health education and nutritional support on the birth outcomes among migrant workers in Maesot, Thailand, recently published in the International Social Science Review.

We worked on this article together because it was important to share with the world how low-cost education and nutritional supplementation can massively improve birth weight and early childhood health. The Charis Project / Shade tree Foundation have been active on such tasks for many years now, and I have be honoured to get to be a part of documenting their great work. To quote the first author Wayland: “These approaches aren’t limited to developing countries. They are as relevant in inner-city communities in the United States as they are in rural Thailand and Myanmar.”

Used by permission: Charis Project / Shade Tree Foundation.

The acknowledgment section of the article didn’t make it through proofing, so I put that material here on my website. We wanted to thank Zohreh Bayatrizi for being an early reader of the article and providing great feedback, and for TinTin’s efforts in helping us meticulously work through all of the data we had – she spend many days enduring my rather thorough questions. These questions extended beyond what we put in the article, and helped Charis reorganize their records. I am also grateful that UC permitted me to spend some of my Sabbatical time on this task as it is outside of my usual research focus. In addition, Pi Gamma Mu has proven itself dedicated to making excellent social science research freely available. In an age of far too many important articles behind paywalls, I am glad that this article is not, and I would like to thank Pi Gamma Mu and all of their alumni for making this possible.


Here is presented a retrospective review of the Charis Project’s Family Engagement Program (FEN) as it existed in 2014-2017. FEN was a program of women’s health education, nutrition supplements, and family visitation. The education program consisted of a 12-week course on nutrition, maternity, and sex education taught individually and in groups, focusing on pregnant Burmese migrant laborers, but including approximately 20 percent male participation. The nutrition supplements consisted of 5 kilograms of fresh vegetables and 12 eggs weekly to pregnant mothers, from course onset to about six months after childbirth depending on family needs. Family visitation took place during food deliveries, and focused on individual counselling and family stability. The program served 39 families from 2014-2017. FEN did not reduce neonatal mortality (due to a miscarriage and severe congenital birth defect), but resulted in all surviving infants being born normal weight and surviving to the end of 2019, representing a significant improvement over the 25.6 percent low birth weights reported for Kayin State, Myanmar.

Phonological contrast and phonetic variation: the case of velars in Iwaidja

Jason A. Shaw, Christopher Carignan, Tonya Agostini, Robert Mailhammer, Mark Harvey and I have recently had an article on Iwaidja accepted to Language. The article is now out, is an open publication, and can be accessed at project MUSE here.

Figure 3 from the article

It was a privilege to be a part of this project!. The article represents several years of work on the part of all of us – my part seeming to me to be the least of all. We acknowledge a host of granting agencies, lab supporters, and researchers, but most of all the Iwaidja speakers: Charlie Mangulda, David Cooper, James Cooper, Henry Guwiyul, Ilijili Lamilami, Isobel Lamilami, and Maggi Maburnbi for sharing the Iwaidja language and culture. (For those of you who don’t know, Iwaidja is an endangered Australian Language from NorthWest Australia.) The abstract itself summarizes the article succinctly.


A field-based ultrasound and acoustic study of Iwaidja, an endangered Australian aboriginal language, investigated the phonetic identity of non-nasal velar consonants in intervocalic position, where past work had proposed a [+continuant] vs [-continuant] phonemic contrast. We analyzed the putative contrast within a continuous phonetic space, defined by both acoustic and articulatory parameters, and found gradient variation from more consonantal realizations, e.g. [ɰ], to more vocalic realizations, e.g. [a]. The distribution of realizations across lexical items and speakers did not support the proposed phonemic contrast. This case illustrates how lenition that is both phonetically gradient and variable across speakers and words can give the illusion of a contextually restricted phonemic contrast.

The articulation of /ɹ/ in New Zealand English

Matthias Heyne, Xuan Wang, myself (Donald Derrick), Kieran Dorreen, and Kevin Watson have recently had an article documenting the articulation of  /ɹ/ in New Zealand English.

This work is therefore in part a follow-up to some of my co-authored research into biomechanical modelling of English  /ɹ/ variants, indicating that vocalic context influences variation through muscle stress, strain, and displacement.  It is, by these three measures, “easier” to move from an /i/ to a tip-down /ɹ/ , but from /a/ to a tip-up /ɹ/.

In this study, for speakers who vary at all (some only do tip-up or tip-down), they are most likely to produce tip-up /ɹ/ in these conditions:

back vowel > low central vowel > high front vowel

initial /ɹ/ > intervocalic /ɹ/ > following a coronal (“dr”) > following a velar (“cr”)

The results show that allophonic variation of NZE /ɹ/ is similar to that in American English, indicating that the variation is caused by similar constraints.  The results support theories of locally optimized modular speech motor control, and a mechanical model of rhotic variation.

The abstract is repeated below, with links to articles contained within:

This paper investigates the articulation of approximant /ɹ/ in New Zealand English (NZE), and tests whether the patterns documented for rhotic varieties of English hold in a non- rhotic dialect. Midsagittal ultrasound data for 62 speakers producing 13 tokens of /ɹ/ in various phonetic environments were categorized according to the taxonomy by Delattre & Freeman (1968), and semi-automatically traced and quantified using the AAA software (Articulate Instruments Ltd. 2012) and a Modified Curvature Index (MCI; Dawson, Tiede & Whalen 2016). Twenty-five NZE speakers produced tip-down /ɹ/ exclusively, 12 tip-up /ɹ/ exclusively, and 25 produced both, partially depending on context. Those speakers who produced both variants used the most tip-down /ɹ/ in front vowel contexts, the most tip- up /ɹ/ in back vowel contexts, and varying rates in low central vowel contexts. The NZE speakers produced tip-up /ɹ/ most often in word-initial position, followed by intervocalic, then coronal, and least often in velar contexts. The results indicate that the allophonic variation patterns of /ɹ/ in NZE are similar to those of American English (Mielke, Baker & Archangeli 2010, 2016). We show that MCI values can be used to facilitate /ɹ/ gesture classification; linear mixed-effects models fit on the MCI values of manually categorized tongue contours show significant differences between all but two of Delattre & Freeman’s (1968) tongue types. Overall, the results support theories of modular speech motor control with articulation strategies evolving from local rather than global optimization processes, and a mechanical model of rhotic variation (see Stavness et al. 2012).


My name is Donald Derrick, and this web-site is dedicated to presenting my research on speech production and perception.

On the production side, I examine vocal tract motion (both shape and muscle position), air flow, oral and nasal acoustics, and visual face motion. I then use this production information to study audio, visual, and tactile speech perception. The purpose is to identify constraints on low level production, and low level percepts that can enhance or interfere with speech perception.

This research has helped identify constraints such as gravity, muscle elasticity, and end-state-comfort on speech production and brought in true multi-modal speech perception research by adding (aero)-tactile speech into audio-visual speech study. I have used this research to expand our understanding of the nature of speech perception, and have been working on commercialization of the use of air flow in enhancement of speech perception, as well as recording oral, nasal, and air flow outputs in speech without the use of masks or other stigmatizing measurement systems.

I am, as of 2017, working on a sonority scale for visual and tactile speech, as well as a both behavioral and brain research on audio-visual-tactile speech in coordination with the University of Canterbury’s Speech lab.

The end-goal is to form a true multi-sensory understanding of speech production and perception that does not ignore or minimize any of our senses.