Facial, external air-flow, and external saliva-droplet motion during speech

Room 120, ground floor, Mechanical Engineering lab wing, University of Canterbury

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To participate, contact Dr. Donald Derrick:

Information Sheet

Audio, Facial, and External Air Flow During Speech

My name is Dr. Donald Derrick, a researcher/lecturer at the University of Canterbury’s New Zealand Institute of Language, Brain, and Behaviour (NZILBB).  Prof. Mark Jermy from Mechanical Engineering, Prof. Jeanette King, Aotahi, PhD student Peiman Pishyar-Dehkordi and I are all part of this research team.

You have been invited to take part in a study of how your face moves and how air flow leaves your mouth and nose as you produce audible speech.  This project is being conducted in part to study how far air flow spreads during speech to aid in our understanding of speech syllable structure as well as the spread of infectious diseases such as Covid-19.

If you choose to take part in this study, your involvement in this project will be to say individual words and phrases, spoken at normal and loud volumes, while having: 1) Your speech audio recorded with a head mounted microphone. 2) Your face illuminated by red light and recorded in high-speed video. 3) Your face profile illuminated by green light and schlieren air flow recorded in high-speed video.

In the performance of the tasks and application of the procedures there are risks of exposing your eyes to high intensity light.  We mitigate this risk by having you wear X4Combat shade 5 safety goggles. They allow you to see darkly yet protect your eyes from the red light in your face.  We also mitigate the risk of spreading disease by cleaning the X4Combat safety goggles with alcohol wipes between use.

You will receive a $20 Westfield voucher for your participation for each language we record. Participation is voluntary and you have the right to withdraw at any stage without penalty. You may ask for your raw data to be returned to you or destroyed at any point. If you withdraw, I will remove information relating to you. However, once today’s data collection is complete, analysis will begin in early 2023, and it will then become increasingly difficult to remove the influence of your data on the results of experiments.

The results of the project may be published.  While we will not publish your identity without your consent, there is a risk that you will be identifiable to people who already know you. The data collected involves recording your voice and face, and that data will be made available in Peiman’s thesis, in journal publications, and in public/media disclosures of this research. A thesis is a public document and will be available through the UC Library. We are also seeking to place the recordings in open-access supplementary materials for our journal articles and ask for specific permission to do so in the consent form below, permission which you can refuse to give even if you consent to the rest of this research.

Please indicate to the researcher on the consent form if you would like to receive a copy of the summary of results of the project.

The project is being carried out in part as a requirement for a PhD thesis by Peiman Pishyar-Dahkordi under the supervision of Dr. Donald Derrick, Prof. Mark Jermy, and Prof. Jeanette King. Dr. Derrick can be contacted at  He will be pleased to discuss any concerns you may have about participation in the project.

This project has been reviewed and approved by the University of Canterbury Human Ethics Committee, and participants should address any complaints to The Chair, Human Ethics Committee, University of Canterbury, Private Bag 4800, Christchurch (

If you agree to participate in the study, you are asked to complete the consent form and return it to the researcher conducting this experiment.

Background Questions

Facial, external air-flow, and external saliva-droplet motion during speech

Participant code:                                                                                 Date:


1. What age group do you belong to:

< 20      20-25      26-30      31-40      41-50      51-60      61-70      71-80      81-90      91+

2. You are:

      female       male     other  ___________

3. Where did you grow up? ………………………………………………………………..

4. Which languages did you learn before you were 5 years old?

5. Which languages did you learn as an adult? (Please indicate your level of proficiency in each).

6.  Do you have difficulty with your hearing?

      yes        no

7. Do you have difficulty following TV programs at a volume others find acceptable?      

     no        slight        moderate        great

8. Do you have difficulty having a conversation with several people in a group or in a noisy environment?     

     no        slight        moderate        great

Positive answers to questions 6, 7 and 8 are possible indicators of some hearing impairment. They do not disqualify people form participating.  If you have concerns about your hearing, please contact the University of Canterbury Speech and Hearing Clinic, Engineering Road, University of Canterbury, Ilam, Christchurch, and we will help you set up an appointment.

In addition, you may at any time withdraw from the project, including withdrawal of any information you have provided, and there were be no personal consequences of any kind for withdrawal from the project.

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