towards the usage of pauses in audio-described videos

Towards the usage of pauses in audio-described videos

Benoît Encelle, Magali Ollagnier-Beldame, Yannick Prié

[email protected]

[email protected]

[email protected]

W4A 2013, May 14th, Rio de Janeiro

W4A13 - Towards the usage of pauses in audio-described videos, Benoît Encelle - 1

Context: growth of available Web Context: growth of available Web videos videos YouTube stats

Today: 72H of videos are uploaded every minute on YouTube (cf. YouTube Statistics)

YouTube blog

- 2 W4A13 - Towards the usage of pauses in audio-described videos, Benoît Encelle

Context: classical accessibility solutions for video Context: classical accessibility solutions for video in general and their limits for Web videosin general and their limits for Web videos Classical solutions for video accessibility…

Visually impaired / blind people : audiodescription

Video audio-descriptions consist in recorded text pronounced by actors, aligned with gaps in the original soundtrack of the video

Hearing impaired / deaf people : subtitling/close-captioning/sign translation

Focus: classical audio description applicability to Web videos ? Money and time consuming (in France 5000 € for a 90 min.

movie, one month) Can not be personalized (one size fits all approach) Only one modality: the audio verbal one, no usage of parallel

communication possibilities

“Low-costs” and innovative solutions have to be developed for improving the accessibility of Web videos


GoalMaking video a first-class citizen of the

accessible web

Meanscombine signal processing and crowdsourcing

for producing textual descriptions of key visual/audio elements of videos (not detailed here)

Investigate the usage of innovative modalities for presenting these descriptions (innovative video enrichments) - 4 W4A13 - Towards the usage of pauses in audio-described videos, Benoît Encelle

Context: the ACAV projectContext: the ACAV project

Extending audiodescription with Extending audiodescription with artificial pausesartificial pauses

Limit of the classical audiodescription process: amount of transmitted descriptions Each audio-description has to fit in its associated gap of the

original soundtrack whatever the amount of key visual content

Choices have to be made with regards to the balance between content description and available gaps, sometimes resulting in the loss of useful descriptions

Proposition: extending gaps with pauses to transmit more and/or more verbose audio-descriptions A given gap can be followed by an « artificial » pause (i.e. a

pause in the video stream)

For such gaps : the associated audio-description will be transmitted during the gap and will go on during an indicated pause duration


Experimentation goal and hypothesisExperimentation goal and hypothesis

Experimentation GoalInvestigate the potential usefulness of these pauses, measuring the level of discomfort that they may produced

Hypothesis and associated variableH1: The longer the pause duration is, the more disturbing it is – (pause duration variable) : to measure a potential pause duration threshold beyond which viewer felt discomfort

H2: The higher the pause ranking number is, the less disturbing it is – (pause location variable) : to measure a potential appropriation effect of enrichments of kind “artificial pause”

H3: Pauses are more disturbing during the first viewing of an enriched video rather than during its second viewing – (viewing number variable) : to measure a potential appropriation effect of the material


Experimental material

Material: 3 different enriched versions of a videoChosen video : a nearly unknown cartoon (8 min 59 sec long)1.Audio-description requirements41 key visual elements have to be described : 41 short

descriptions were associated to gaps

1.Audio-described video : artificial pauses requirements26 descriptions are too “long” / associated gap duration : 26

artificial pauses were added at the end of these gaps

1.Enriched versions of the videoAs we want to test 3 different kinds of pause durations (D1, D2

and D3) and independently test variables pause duration and pause location, three versions of the enriched video (including audio-descriptions and artificial pauses) were produced


Experimentation: protocol, Experimentation: protocol, participantsparticipants

Protocol3 groups of subjects (one for each enriched video

version), two viewings of the corresponding enriched video version

Each subject was in front of a PC and has to indicate during each viewing, each time he felt discomfort with an artificial pause (by pressing a dedicated keyboard key)

Questionnaire to collect subject feedbacks

Participants18 unpaid legally blind volunteers (12-69 years old, 9

males and 9 females)


Results: quantitative oriented study H1: The longer the pause duration is, the most

disturbing it is

Chi-square test p-value = 0,71995 > 0,05

No dependency between the pause duration and number of discomforts variables

Pause duration (according to our definition, i.e. maximal pause duration, D3, is equal to 1,5 * associated gap duration) seems to have no impact on the perception of discomforts


Number of discomforts / pause durations

D1 D2 D3 Total discomfort 22 21 26 69 not discomfort 290 291 286 867

Total 312 312 312 936

Results: quantitative oriented study H2: The higher the pause ranking number is, the less disturbing

it is

Chi-square test p-value = 0,00588 < 0,05 Dependency between the pause location and number of discomforts

variables Pause location seems to have an impact on the perception of

discomforts - 10 W4A13 - Towards the usage of pauses in audio-described videos, Benoît Encelle

Results: quantitative oriented study H3: Pauses are more disturbing during the first viewing of an

enriched video rather than during the second viewing

Chi-square test p-value = 0,00862 < 0,05

Dependency between the viewing number and number of discomforts variables

Viewing number of the enriched version of the video seems to have an impact on the perception of discomforts


DiscussionDiscussion Pause duration

No threshold found but more experimentations have to be conducted

Pause location maximum of discomforts not associated to the 1st pause : short subjects’ adaptation delay to video enrichments of kind « artificial pause » ?Discomfort slowly decrease along time : a potential appropriation effect of « artificial pauses » video enrichments ?

Number of viewingsNumber of discomforts strongly decreases between two viewings : an appropriation effect of the material (an enriched video) ?


ConclusionConclusion

Exploratory work : first investigation on the usage of pauses in audio-described videos

Promising results : artificial pauses offer a good acceptability level as well as a low disturbing effect


Some future workSome future work Is there an appropriation effect of the

artificial pauses enrichment across different kinds of videos (i.e. different genres, durations, etc. ) ?Are people less likely to perceive discomfort as a result of extended pauses as they become more used to view this kind of material ?

In-depth study of artificial pauses utility in terms of video story understandingComparative study between several versions of the video (e.g. without enrichments, with classical audio-descriptions, with audio-descriptions + artificial pauses) - 14 W4A13 - Towards the usage of pauses in audio-described videos, Benoît Encelle

Thank you ! Questions ?Thank you ! Questions ?

Benoît EncelleUniversité de Lyon,

CNRS Université Lyon 1, LIRIS Lab [email protected]


towards the usage of pauses in audio-described videos

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