Effects of Audio-Video Asynchrony on
Viewer’s Memory, Evaluation of Content andDetection Ability

Research Report Prepared for
Pixel Instruments

Byron Reeves
David Voelker

Stanford UniversityOctober 1993

Effects of Audio-Video Asynchrony on Viewer's Memory,
Evaluation of Content and Detection Ability
Research Questions:
1. Does audio-video asynchrony change viewers' evaluation of television content, andmemory for television content?
2. Can viewers detect audio-visual asynchrony in television programs?
Experimental Methods:
1. Laboratory experiment: conducted at Stanford University.
2. Procedure: People viewed three different versions (no asynch, 2.5 fields asynch, 5fields asynch) of six television segments. After each segment, viewers evaluated thespeakers in the segments. After viewing all segments, viewers were tested for memory of
the segments, and they were asked if they could detect synchronization problems in thesegments.
3. Subjects: 18 adults between the ages of 19 and 45; half men, half women.
4. Equipment: All video material was shown to single viewers on a rear-projection screen
using a 3/4 in Sony U-Matic with an Eiki video projector. Subjects were seated 7 feetfrom the screen and viewed a 24 inch high picture.
5. Manipulation of audio-video synchronization:
Version #1 -- Perfect audio-video synchronization
Version #2 -- Audio preceded video by 2.5 video fields
Version #3 -- Audio preceded video by 5 fields
6. Description of stimuli:
Message #1 -- Fitness Center ad (male and female announcers)
Message #2 -- Jewelry store ad (male announcer)
Message #3 -- News story about computers (female announcer)
Message #4 -- Ad for radio station (female announcer)
Message #5 -- News story with woman senator as featured speaker
Message #6 -- News story about federal budget (female newscaster)7. Measures of evaluation:
Eight 8-point scales evaluating main speaker (see questionnaire):
Effective
Understandable
Pleasant
Influential
Bungling
Aggravating
Intelligible
Agitated

Ineffective
Confusing
UnpleasantUninfluential
Skillful
Soothing
Unintelligible
Calm

Eight 8-point scales evaluating the overall presentation:
Well produced
Unsuccessful
Fast
LikableUnpersuasive
RoughCast well
Good

Poorly produced
Successful
Slow
Unlikable
Persuasive
SmoothCast poorlyBadAll evaluation scales (with the exception of slow/fast) summed for overall positivenegative index.
8. Measures of memory:Three multiple-choice memory questions were asked for each of the six message segments.
All memory questions (18) were then summed into an overall memory index for allinformation.
9. Measures of detection ability:
Two different types of questions asked viewers whether they noticed problems with audiovideo synchronization:
Question 1: "Do you have any comments about the segments that you just viewed?" (Nomention of possible synchronization problems.)
Question 2: "Please indicate in which of the segments you thought that the timing between
audio and video may have been off."
Viewers who mentioned synchronization problems voluntarily constituted a third level ofdetection.

Summary of Results:
1. When audio precedes video by 5 video fields, viewers evaluate people on television
more negatively (e.g. less interesting, more unpleasant, less influential, more agitated,less successful). This difference is not large, but it is statistically significant. (Figures 1and 2)
2. Audio-video asynchrony has no effect on viewer's memory for audio information.
(Figure 3)
3. Viewers can accurately tell when a television segment is in perfect synch, and when itis 5 fields out of synch. Viewers cannot accurately tell the same segments are 2.5 fields
out of synch. (Figure 4)
4. Even though detection is low when asynchrony is moderate (2.5 fields), viewer
evaluations are still affected.

Implication results
1. Audio - visual asynchrony does not inhibit memory for television material, its changes
evaluations of television content.
There are two competing theories about how audio-visual asynchrony could influence thepsychological processing of television. One view is that asynchrony is confusing, andtherefore interferes with thoughtful processing of information. This interference could
then preclude the mental rehearsal and elaboration necessary to remember material;
hence, asynchrony causes poor memory.
A second view is that asynchrony is unconsciously disturbing. The experience of this
disturbance (which is experienced as bad feelings) is then transferred to the primarycontent of the messages; hence, asynchrony causes negative evaluations of speakers andmaterial with little or no conscious awareness of the effect.
The data in this experiment support the second theory. There were no effects ofasynchrony on memory, and if anything memory was slightly better when the messages
were maximally out of sync (perhaps because asynchrony attracts greater attention). But
significant negative effects were found for the influence of asynchrony on evaluation oftelevision segments and people in them.
Based on this experiment, the following could be said about the necessity of correcting
synchronization errors: The presence of audio-video asynchrony will cause material to be
negatively evaluated and remembered well - perhaps the worst commercial outcome of apersuasive message.

2. Awareness of audio-video asynchrony is not necessary for synchronization problems
to have psychological effect.
Half of the subjects could identify the synch problems and half could not, yet bothgroups were affected by the problem. Therefore, an appropriate criterion for judging
the need for asynch correction is not the subjective awareness of average viewers oreven technicians. Rather, the correction is justified because of this experiment which
was able to demonstrate effects that viewers were unable to define or discuss.
3. The magnitude of the effect of audio-video asynchrony is statistically small but quite
large to the cost of correction.
The size of differences in the experiment were small. Even though differences were
not due to chance, the differences only accounted for small amount of the variation in
evaluation of television content. So it’s only fair to say that many othercharacteristics of television content, and methods of presenting content are more
important than the degree of synchronization studied in this experiment.
However, the size of the synchronization effect is certainly large to the dollar cost ofcorrecting the problem. There are not many points in the post-production oftelevision where significant negative effects can be precluded with an easy andrelatively cheap intervention.

The Effect of Audio-Video Asynchrony
on Evaluation of Segments

Figure 1

The Effect of Audio-Video Asynchrony
on Evaluation of Individual Segments

Figure 2

The Effect of Audio-Video Asynchrony on Memory

Figure 3

Number of Correct Identifications of A/V Asynchronyby Individual Segments

Figure 4

Number of Subjects who Noticed That Some Spots Were
Out of Sync

Figure 5Television Study

Thank you for participating in this study. We’re interested in how viewers
evaluate people who have seeking roles on TV. I’m going to show you several
brief segments of people talking. After each segment, we’ll pause briefly sothat you can answer a few written questions about the featured speaker.
Some of the segments have more than one person talking. We’re mostinterested in the main person who is speaking each segment, and that’s theperson we’ll ask you to evaluate.
We’ll do a practice segment first.

Practice Segment
Listed below are pairs of words that are opposite in meaning. For each word pair, pleasecircle the number that best corresponds to your opinion of the man who is the mainspeaker.

I thought the man was…
1. Understandable

1

2

3

45678

Confusing

2. Ineffective

12

3

4

5

6

78

Effective

3. Pleasant

12

3

4567

8

Unpleasant

For each of the following word pairs, please circle the number that best corresponds toyour opinion of the overall presentation.
I thought the overall presentation was…
4. Well produced

12345678

Poorly produced

5. Unsuccessful

12345678Successful

6. Fast12345678Slow

Jewelry store commercial
Listed below are pairs of words that are opposite in meaning. For each word pair, pleasecircle the number that best corresponds to your opinion of the man who is the mainspeaker.
I thought the man was…
1. Understandable

12345678Confusing

2. Ineffective

12345678Effective

3. Pleasant12345678

Unpleasant

4. Influential

12345678

Un-influential

5. Bungling

12345678

Skillful

6. Aggravating

12345678Soothing

7. Intelligible

12345678

Unintelligible

8. Agitated12345678Calm

For each of the following word pairs, please circle the number that best corresponds toyour opinion of the overall presentation.
I thought the overall presentation was ...
9. Well produced

12345678

Poorly produced

10. Unsuccessful

12345678Successful

11. Fast

12345678Slow

12. Likable

12345678

Unlikeable

13. Unpersuasive12345678

Persuasive

14. Rough12345678

Smooth

15. Cast Well

12345678

Cast Poorly

16. Good

12345678

BadBudget news story
Listed below are pairs of words that are opposite in meaning. For each word pair, pleasecircle the number that best corresponds to your opinion of the anchorperson.
I thought the anchorperson was…

1. Understandable

12345678Confusing

2. Ineffective

12345678

Effective

3. Pleasant12345678

Unpleasant

4. Influential

12345678

Uninfluential

5. Bungling

12345678

Skillful

6. Aggravating

12345678Soothing

7. Intelligible

12345678

Unintelligible

8. Agitated12345678Calm

For each of the following word pairs, please circle the number that best corresponds toyour opinion of the overall presentation.
I though the overall presentation was…

9. Well produced12345678

Poorly produced

10. Unsuccessful

12345678Successful

11. Fast

12345678Slow

12. Likable

12345678Unlikeable

13. Unpersuasive12345678

Persuasive

14. Rough12345678Smooth

15. Cast Well

12345678

Cast Poorly

16. Good

12345678Bad

Radio station night out
Listed below are pairs of words that are opposite in meaning. For each word pair, pleasecircle the number that best corresponds to your opinion of the woman who is the mainspeaker.
I thought the woman was…

1. Understandable

12345678Confusing

2. Ineffective

12345678

Effective

3. Pleasant12345678

Unpleasant

4. Influential

1234

5678

Uninfluential

5. Bungling

12345678

Skillful

6. Aggravating

12345678Soothing

7. Intelligible

12345678

Unintelligible

8. Agitated12345678CalmFor each of the following word pairs, please circle the number that best corresponds toyour opinion of the overall presentation.
I though the overall presentation was…
9. Well produced

12345678

Poorly produced

10. Unsuccessful

12345678

Successful

11. Fast

12345678Slow

12. Likable

12345678

Unlikeable

13. Unpersuasive12345678

Persuasive

14. Rough12345678

Smooth

15. Cast Well

12345678

Cast Poorly

16. Good

12345678

BadWoman senator speech
Listed below are pairs of words that are opposite in meaning. For each word pair, pleasecircle the number that best corresponds to your opinion of the speaker.
I thought the speaker was…

1. Understandable

12345678Confusing

2. Ineffective

12345678

Effective

3. Pleasant12345678

Unpleasant

4. Influential

12345678

Uninfluential

5. Bungling

12345678

Skillful

6. Aggravating

12345678Soothing

7. Intelligible

12345678

Unintelligible

8. Agitated12345678CalmFor each of the following word pairs, please circle the number that best corresponds toyour opinion of the overall presentation.
I thought the overall presentation was…

9. Well produced

12345678

Poorly produced

10. Unsuccessful

12345678

Successful

11. Fast

12345678Slow

12. Likable

12345678

Unlikeable

13. Unpersuasive12345678

Persuasive

14. Rough12345678

Smooth

15. Cast Well

12345678

Cast Poorly

16. Good

12345678BadFitness club commercial
Listed below are pairs of words that are opposite in meaning. For each word pair, pleasecircle the number that best corresponds to your opinion of the woman in the commercial.
I thought the woman was…

1. Understandable

123

45678

Confusing

2. Ineffective

1234

5678

Effective

3. Pleasant12345678

Unpleasant

4. Influential

1234

5678

Uninfluential

5. Bungling

12345678

Skillful

6. Aggravating

12345678

Soothing

7. Intelligible

12345678Unintelligible

8. Agitated12345678Calm

For each of the following word pairs, please circle the number that best corresponds toyour opinion of the overall presentation.
I thought the overall presentation was…

9. Well produced

12345678

Poorly produced

10. Unsuccessful

12345678

Successful

11. Fast

12345678Slow

12. Likable

12345678

Unlikeable

13. Unpersuasive12345678

Persuasive

14. Rough12345678Smooth

15. Cast Well12345678

Cast Poorly

16. Good

12345678

BadComputer privacy story

Listed below are pairs of words that are opposite in meaning. For each word pair, pleasecircle the number that best corresponds to your opinion of the anchorperson.
I thought the anchorperson was…

1. Understandable

12345678

Confusing

2. Ineffective

12

34

5678

Effective

3. Pleasant12345678

Unpleasant

4. Influential

12345678

Uninfluential

5. Bungling

12345678

Skillful6. Aggravating

12345678Soothing

7. Intelligible

12345678

Unintelligible

8. Agitated12345678CalmFor each of the following word pairs, please circle the number that best corresponds toyour opinion of the overall presentation.
I thought the overall presentation was…

9. Well produced

12345678

Poorly produced

10. Unsuccessful

12345678

Successful

11. Fast

12345678Slow

12. Likable

12345678

Unlikeable

13. Unpersuasive12345678Persuasive

14. Rough12345678Smooth

15. Cast Well

12345678Cast Poorly

16. Good12345678BadListed below are some lines of dialog from the segments you saw. Each line has four
possible completing phrases. In each group, only one of the phrases was actually spoken
in that position; the other three were not. Please circle the phrase that you think wasactually spoken. Try to match the exact wording of the phrase that was spoken in thesegment. If you can’t remember exactly, please circle your best guess.

Fitness club commercial

1.”24-Hour Nautilus has a…

manager’sOnce-in-a-lifetime
Miraculous
Heart-pumping...special happening now.’

2. “Now you can start working out… to look your best.”
To tone up and slim down.”
To get in shape.”
For less than you’d expect.”3.
“A great“The ideal… workout for the perfect price.”“The perfect“The ultimate

Jewelry store commercial
4. “You could even win a…

diamond solitaire.”
Thousand-dollar watch.”
Hawaiian vacation.”24-carat gold bracelet.”

5. “The Diamond Center’s…

Easter egg
win-a-prizeAnniversaryHoliday…extravaganza is underway.”

6. “We’ve got credit, we’ve got prizes, and we have… four convenient locations.”
Low, low prices.”
Beautiful jewelry.”
Lots of inventory.”

Computer privacy story
7. “Internal documents suggest the Resolution Trust Corporation’s top lawyer approved...
a committee’s examination of an employee’s records.”
A secret check of an employee’s computer.”
An anonymous inquiry into employee bank accounts.”
A secret study of employee computer files.”8. “The RTC claimed it wanted to see if…

Brian Patterson
Bruce Paterson
Bruce Patterson
Brian Paterson...violated policy byUsing government computers for personal business.”
9. “Federal law allows such checks only…

with permission of the user.”
When authorized by federal court.”
In theft or espionage cases.”
In felony cases.”

Radio station night out
10. “We’re partying tonight with Bay Area Night Out here at the... Oasis Café.”
Mile High Club.”
Cadillac Club.”
Hot Rod Café.”
11. “Wanna give it up for my main man…

revvin’ it up tonight…”
who’s spinning the discs tonight…”
puttin’ us in the mix tonight…”
waxing the tracks tonight…”

12. “KMEL power mixer Billy Vidal is…

mixing music tonight.”
In the house.”
Manning the booth.”Your host tonight.”

Woman senator speech
13. “What I worry most about today is engaging people in a way…
that provides a sense of fulfillment.”
In which they’re willing to participate.”That makes them feel government is responsive to them.”That maximizes their personal involvement.”
14. “They’re willing to…

go door-to-door.”
Pound the pavement
Give up something in order to get something.”
Work long hours at phone banks.”

15. “It’s hard to engender that kind of… motivation and drive ...for a moderate position
personal excitement
principled commitment
spark and enthusiasm

Budget news story
16. “The Clinton administration has abandoned plans for a…BTU tax”
natural gas tax”
broad-based energy tax”
comprehensive gas tax”
17. “The…

18.

Senate’s budget bill ...substitutes a 4.3-cent increase in the gas levy.”
Republican alternative
National Energy Council’s proposal
Energy secretary’s recommendation“The Washington Post
“President Clinton“Press secretary Dee Dee Myers“Budget Director Leon Panetta…says the administration will favor a compromise closer to the Senate version”
PLEASE DO NOT TURN THE PAGE UNTIL REQUESTED

In some of the segments you saw, the timing of the audio with the video may have been
off. Please indicate in which of the segments, if any, you think the timing was off (or“out of sync”). The segments may be listed in an order different from the order in which
you saw them.
Circle one for eachJewelry store commercial:in sync

out of sync

don’t know

Budget news story:

in syncout of sync

don’t know

Radio station night out:

in sync

out of sync

don’t know

Woman senator speech:in sync

out of sync

don’t know

Fitness club commercial:in sync

out of sync

don’t know

Computer privacy story:

in sync

out of sync

don’t know