# Stimulus Creation

**Recording Auditory Stimuli**: Once a script has been decided you will need to record the stimuli for the study. Usually you will need to find a voice actor (usually female unless otherwise specified) who is perfectly bilingual in English and French (no detectable foreign accent in either) because both stimuli sets should be recorded by the same actor. The voice actor should be someone who will not be testing for that particularly study (i.e., avoid using lab members as voice actors).

§  Recording locations: The lab has in the past recorded stimuli either in the lab (using our USB microphone and sound shield) or in soundbooths located in other locations.

For high-quality recordings, the ideal location to record the stimuli is at CRBLM at the BRAMS Lab ([http://www.crblm.ca/centre/facilities/brams\_laboratory](http://www.crblm.ca/centre/facilities/brams_laboratory)) because Krista is an associate member we get free access to their recording equipment but you will need to coordinate with the coordinator to set up a recording time when the technicians are available to help since you will be using professional recording equipment.

If BRAMS is not available you can record at Concordia’s Centre for Digital Arts ([http://cda.concordia.ca/index.php/contact-us](http://cda.concordia.ca/index.php/contact-us) - contact Cristobal Urbina). There is typically a fee for Fine Arts students to use their facilities but because we very rarely record stimuli they have made exceptions for us in the past.

Note that the Communications Department, although they have a recording booth, does not allow us to use their facilities (reserved for Communications students)

* Remember to have the **voice actor fill out a language background questionnaire** as this information may be used in publications when describing the stimuli used.
* In the past our audio stimuli is **edited using Praat**. Praat can be used to isolate, splice, combine and manipulate sound clips. Praat manuals are easily found online but RAs should create their own How To guides as they go and save those to the server to be accessed for future studies.
* Note that the **loudness of all our audio stimuli is set to 70 dB**.&#x20;
* If you use Audacity to record, you should go to Audio Setup first, and select Mono for the recording channel and ensure that the USB microphone (RODE) is selected in Recoding Devices.   &#x20;

**Creating Visual Stimuli**: On the lab server (Server Location: IRL Server – Visual Stimuli - Images) there is an image bank for images that we have used in previous studies. Try to use these images as much as possible. If not search for images using Google images or other image search engines and edit them in Gimp so that the background is clear and can be transposed on any colour background (see How To Powerpoint; Server Location: IRL – How To Documents – How to Use Gimp). Make sure you search for _High Resolution_ images, there is an option that you can check off on Google Images to only yield high resolution results.

**Creating Audiovisual Stimuli:** For studies run on the Tobii, the audio recordings and visual stimuli (images or videos) need to be combined before being uploaded onto the eyetracker as a single file. Each trial will need to saved as its own file. In the past we have used Adobe Premiere and Lightworks to do this. In the How To Documents folder on the IRL Server there are Youtube videos created by L. Rebner on how to use Lightworks and Adobe Premiere guidelines for certain effects (e.g., adding motion to static image). For studies run on the Eyelink, this step is not necessary

**Stimuli Documentation:** It will be important to keep track of the stimuli properties in a spreadsheet that can be referred to later (e.g., fundamental frequency of the selected clips, clip length, etc).
