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Speech User Interfaces
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Outline
Motivation for speech UIs Speech recognition UI problems with speech UIs SpeechActs: Guidelines for speech UIs Speech UI design tools Multimodal UIs
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Motivation for Speech UIs:Pervasive Information Access
Information
&
Services
I-Land vision by Streitz, et. al.
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UIs in the Pervasive Computing Era
Future computing devices won’t have the same UI as current PCs wide range of devices
small or embedded in environment often w/ “alternative” I/O & w/o screens information appliances
I-Land vision by Streitz, et. al.
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Information Access via Speech
Read my important
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Industry Leaders
Nuance Corporation Applications: TellMe, … Users: Government, Computers- Microsoft,
IBM,
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Speech UI Motivation
Smaller devices -> difficult I/O people can talk at ~ 90 wpm -> high speed
“Virtually unlimited” set of commands Freedom for other body parts
imagine you are working on your car & need to know something from the manual
Natural evolutionarily selected for
reading, writing, & typing are not (too new)
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Why are Speech UIs Hard to Get Right?
Speech recognition far from perfect imagine inputting commands w/ the mouse &
getting the wrong result 5-20% of the time Speech UIs have no visible state
can’t see what you have done before or what affect your commands have had
Speech UIs are hard to learn how do you explore the interface? how do you
find out what you can say?
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Speech recognition the computer understanding what the customer is saying
Speech production (or synthesis) the computer talking to the customer
Speech UIs Require
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Speech Recognition Continuous vs. non-continuous Speaker independent vs. dependent Speech often misunderstood by people
feedback via speech, facial expressions, & gesture Recognizers trained with real samples
often get gender-based problems Based on probabilities (HMMs - Bayes)
trigrams of sounds or words Several popular recognizers
Nuance, SpeechWorks, IBM ViaVoice
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Speech Production
Three frequency regions of great intensity visible on oscilloscope come from larynx, throat, mouth
Two needed for recognition but “tinny” Can generate emotion affect in speech
Demo anger, disgust, gladness, sadness, fear, & surprise
http://cahn.www.media.mit.edu/people/cahn/emot-speech.html
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Recognition Problems
Good recognition humans < 1% error rate on dictation top recognition systems get <1-X% error rates
computers don’t use much context Key is to be application specific for lower error rates
Background noise even worse recognition rates (20-40% error)
Speed Better as hardware getting faster
in 10 years gone from 5 high-end workstations required to some speech systems running on laptops or even PDAs
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More Recognition Problems
Isolated, short words difficult common words become short
Segmentation silly versus sill lea
Spelling mail vs. male -> need to understand language
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Speech UI Problems Speech UI no-nos
modes (no feedback) certain commands only work when in specific states
deep hierarchies (aka voice mail hell) Verbose feedback wastes time/patience
only confirm consequential things use meaningful, short cues
Interruption half-duplex communication (i.e., no barge-in support)
Too much speech on the part of customer is tiring Speech takes up space in working memory
can cause problems when problem solving
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SpeechActs: Guidelines for Speech UIs
Speech interface to computer tools email, calendar, weather, stock quotes
Establish common ground & shared context make sure people know where they are in the conversation
Pacing recog. delays are unnatural, make it clear when this occurs barge-in lets user interrupt like in real conversations tapering of prompts progressive assistance: short errors messages at first, longer
when user needs more help implicit confirmation: include confirm in next command
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One Vision of Future User Interfaces
Star Trek style UI verbally ask the computer for information may be common in mobile/hands-busy situations problem: hard to design, build, & use!
requires perfect speech recognition & language understanding
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Our Vision of Future User Interfaces
Multimodal, Context-aware UIs multimodal
uses multiple input modalities (speech & gesture) to disambiguate
user says “move it to this screen” while pointing context-aware
apps can be aware of location, user, what they are doing, … people are talking -> don’t rely on speech I/O
Problem: how to prototype & test new ideas? Informal UI Design Tools!
combine Wizard of Oz & informal storyboarding
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Multimodal Error Correction
Dictation error correction study found users are better at correcting recognition
errors with a different input modality recognizer got it wrong the first time -> it will get it
wrong the second time hyperarticulating aggravates
Correct dictation errors with vocal spelling, writing, typing, etc
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Summary
Speech UIs may permit more natural computer access allow us to use computers in more situations are hard to get to work well
lack of visible state, tax working memory, recognition problems, etc.
UI tools are needed for speech UI design Multimodal UIs address some of the problems with
pure speech UIs help disambiguate help w/ correction