[lookit-research] stimulus sound not coming through on videos

Sat Mar 18 13:50:17 EDT 2023

Hi Lisa,

Thanks very much for sharing your experience with Lookit and for pointing out the limitations of what we can expect in terms of recorded sounds and timing.  The one good piece of news in all of this is that if you happen to pick visual stimuli that produce a relatively large change in the overall luminance of the scene, and if the camera recording the participant picks up that change, then you can use this as your cue that the trial has started. Of course, if your stimuli do not increase overall luminance then you’re back to the problem of figuring out when the trial starts and there, based on what you’re reporting, there isn’t a simple solution here. Oh well, one must be realistic about the limits of online testing.

And, I suspect that the intractability of the timing issue is probably due to the variation in the type of connection that the testing computer has to the internet (e.g., wi-fi vs. ethernet) as well as the download speeds of the testing computer (which, of course, is partly determined by the ISP and the type of connection between the computer and the modem/router in the house).

Best regards,
David

From: Lisa Oakes <lmoakes at ucdavis.edu>
Date: Saturday, March 18, 2023 at 1:16 PM
To: "Lewkowicz, David" <david.lewkowicz at yale.edu>
Cc: Melissa Kline <mekline at mit.edu>, "lookit-research at mit.edu" <lookit-research at mit.edu>, "Aslin, Richard" <richard.aslin at yale.edu>
Subject: Re: [lookit-research] stimulus sound not coming through on videos

Hi David (and everyone):

Online testing has such promise and yet has new frustrations.

First, what you are experiencing is not a lookit problem.  Computers suppress what it interprets as background noise when recording. We have found that we hear the sound pretty reliably for some experiments but not for others, and sometimes we hear some sounds but not others. I suspect it depends on the nature of the sound and the volume. Bottom line: it doesn’t matter how you are recording, if you collect data online you can’t depend on hearing the sound of the stimuli.

Moreover, even if you do hear sound, it is likely out of sync with the video. You may notice that when you see a child speak what you hear is out of sync with the video. Again, this is variable and there is no easy way to correct it. This is a known problem with video recording and with Lookit. You can find more info here: https://lookit.readthedocs.io/en/develop/researchers-lag-issues.html<https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flookit.readthedocs.io%2Fen%2Fdevelop%2Fresearchers-lag-issues.html&data=05%7C01%7Cdavid.lewkowicz%40yale.edu%7C70d7851ac5dc41eb240a08db27d4790b%7Cdd8cbebb21394df8b4114e3e87abeb5c%7C0%7C0%7C638147565743157654%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=MiDTNZdQdqh4DV55IILN4R1btd3RJFMhOARUP5WKGQg%3D&reserved=0>
A better solution is to use the timing info provided by lookit. However, this also is not exact. We (and others) have done extensive testing of the timing of stimulus presentations in lookit and have found that there is some variation in when stimuli start relative to when lookit says they start. I don’t think this has been solved and I don’t think it is known why it happens.

We have tested hundreds of kids using online methods for the last 3 years and my recommendations are (1) don’t rely on sound for timing, and (2) online methods are best for stimuli that are static or if it doesn’t matter when the infant looks relative to what is happening in the stimulus.

This probably isn’t the answer you wanted, but I hope it is helpful as you find a solution.

Lisa

Lisa M. Oakes
Professor, Department of Psychology
Faculty Researcher, Center for Mind and Brain
University of California, Davis
267 Cousteau Place
Davis, CA 95618

phone:  530 754-4523 OR
530 754-8304
Pronouns: she/her/hers

[cid:image001.png at 01D959A0.92313C80]

On Mar 18, 2023, at 8:45 AM, Lewkowicz, David <david.lewkowicz at yale.edu<mailto:david.lewkowicz at yale.edu>> wrote:

Dear Melissa,

Recently, we have noticed that the participant videos recorded by Lookit seem to filter out the stimulus sounds that we normally present in our videos. We use these sounds to mark the beginning of a trial when we code the participant videos and, thus, their absence makes it impossible for us to reliably code the participant videos.  Are you aware of this and, if so, is there a fix for this problem?

Thanks very much in advance for looking into this problem.

Best regards,
David & Dick

__________________________________________
David J. Lewkowicz, Ph.D.
Senior Scientist
Haskins Laboratories, New Haven, CT
Yale Child Study Center
Personal: https://haskinslabs.org/people/david-lewkowicz<https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fhaskinslabs.org%2Fpeople%2Fdavid-lewkowicz&data=05%7C01%7Cdavid.lewkowicz%40yale.edu%7C70d7851ac5dc41eb240a08db27d4790b%7Cdd8cbebb21394df8b4114e3e87abeb5c%7C0%7C0%7C638147565743157654%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=7FZIKL%2FYKMjMvxPvUWfBgaWMVeLcK15KBhmgRLpHrsY%3D&reserved=0>
Lab: http://llamblab.haskins.yale.edu/<https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Fllamblab.haskins.yale.edu%2F&data=05%7C01%7Cdavid.lewkowicz%40yale.edu%7C70d7851ac5dc41eb240a08db27d4790b%7Cdd8cbebb21394df8b4114e3e87abeb5c%7C0%7C0%7C638147565743157654%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=JOMur9zdTinqsmqpo3vcJ9Zh0N0IEj1ulApF8286GMc%3D&reserved=0>

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