developing with speech and voice recognition in mobile apps
DESCRIPTION
Can you hear me now? Move over Siri, here comes an army of speech-enabled mobile applications on Windows Phone. Mobile applications are not always easy to work with due to the small screen and small on-screen keyboard. Using our voice is a natural form of communication amongst humans, and ever since 2001: A Space Odyssey, we’ve been dreaming of computers who can converse with us like HAL9000. Or maybe you’re part of the new generation of geeks dreaming of Cortana? Thanks to the new Microsoft SDKs for voice recognition and speech synthesis (aka text-to-speech), we are now several steps closer to this reality. This session explores the development techniques you can use to add voice recognition to your Windows Phone applications, including in-app commands, standard & custom grammars, and voice commands usable outside your app. We’ll also see how your apps can respond to the user via speech synthesis, opening-up a new world of hands-free scenarios. This reality is here, you’ll see actual live demos with speech and you can now learn how to do it.TRANSCRIPT
Nick Landry, MVP
App Artisan
Nokia Developer Champion & Ambassador
@ActiveNick – www.mobility42.com
Developing with Speech and
Voice Recognition in Mobile Apps
talk2me
M3Conference
Who is ActiveNick?
• App Artisan – Mobile Development Consultant – Mobility42
• Microsoft MVP: Windows Phone Development
• Mobile Publisher – Big Bald Apps: http://www.bigbaldapps.com
• Nokia Developer Champion and Ambassador
• Speaker. Blogger. Author. Tweeter. Gamer
• 20+ Years of Professional Experience
• Specialties:
• Mobile Development
• Location Intelligence & Geospatial Systems
• Data Visualization, HPC, Cloud
• Mobile Game Development
• Blog: www.ActiveNick.net
• Twitter: @ActiveNick
Agenda
• Speech on Windows Phone 8
• Speech synthesis
• Controlling applications using speech
• Voice command definition files
• Building conversations
• Selecting application entry points
• Simple speech input
• Speech input and grammars
• Using Grammar Lists
Speech on
Windows Phone 8
Windows Phone Speech Support
• Windows Phone 7.x had voice support built into the operating system
• Programs and phone features could be started by voice commands e.g “Start MyApp”
• Incoming SMS messages could be read to the user
• The user could compose and send SMS messages
• Windows Phone 8 builds on this to allow applications to make use of speech
• Applications can speak messages using the Speech Synthesis feature
• Applications can be started and given commands
• Applications can accept commands using voice input
• Speech recognition requires an internet connection, but Speech Synthesis does not
Speech
Synthesis
Enabling Speech Synthesis
• If an application wishes to use speech output the
ID_CAP_SPEECH_RECOGNITION capability must
be enabled in WMAppManifest.xml
• The application can also reference the Synthesis
namespace
using Windows.Phone.Speech.Synthesis;
Simple Speech
• The SpeechSynthesizer class provides a simple way to produce speech
• The SpeakTextAsync method speaks the content of the string using the default voice
• Note that the method is an asynchronous one, so the calling method must use the
async modifier
• Speech output does not require a network connection
async void CheeseLiker(){
SpeechSynthesizer synth = new SpeechSynthesizer();
await synth.SpeakTextAsync("I like cheese.");}
Selecting a language
• The default speaking voice is selected automatically from the locale set for the phone
• The InstalledVoices class provides a list of all the voices available on the phone
• The above code selects a French voice
// Query for a voice that speaks French.var frenchVoices = from voice in InstalledVoices.All
where voice.Language == "fr-FR"select voice;
// Set the voice as identified by the query.synth.SetVoice(frenchVoices.ElementAt(0));
Demo 1: Speech Synthesis
and Voice Selection
talk2me - http://bit.ly/wpt2m
Speech Synthesis Markup Language
• You can use Speech Synthesis Markup Language (SSML) to control the spoken output
• Change the voice, pitch, rate, volume, pronunciation and other characteristics
• Also allows the inclusion of audio files into the spoken output
• You can also use the Speech synthesizer to speak the contents of a file
<?xml version="1.0" encoding="ISO-8859-1"?><speak version="1.0"xmlns=http://www.w3.org/2001/10/synthesis xml:lang="en-US"><p> Your <say-as interpret-as="ordinal">1st</say-as> request was for
<say-as interpret-as="cardinal">1</say-as> room on<say-as interpret-as="date" format="mdy">10/19/2010</say-as> ,arriving at <say-as interpret-as="time" format="hms12">12:35pm</say-as>.
</p></speak>
Controlling
Applications
using Voice
Commands
Application Launching using Voice command
• The Voice Command feature of Windows Phone 7 allowed users to start applications
• In Windows Phone 8 the feature has been expanded to allow the user to request data
from the application in the start command
• The data will allow a particular application page to be selected when the program starts
and can also pass request information to that page
• To start using Voice Commands you must Create a Voice Command Definition (VCD) file
that defines all the spoken commands
• The application then calls a method to register the words and phrases the first time
it is run
The Fortune Teller Program
• The Fortune Teller program will tell
your future
• You can ask it questions and it will
display replies
• It could also speak them
• Some of the spoken commands activate
different pages of the application and
others are processed by the application
when it starts running
<CommandPrefix> Fortune Teller </CommandPrefix><Example> Will I find money </Example><Command Name="showMoney">
<Example> Will I find money </Example><ListenFor> [Will I find] {futureMoney} </ListenFor><Feedback> Showing {futureMoney} </Feedback><Navigate Target="/money.xaml"/>
</Command><PhraseList Label="futureMoney">
<Item> money </Item><Item> riches </Item><Item> gold </Item>
</PhraseList>
The Voice Command Definition (VCD) file
• This is the “money” question: “Fortune Teller Will I find money”
<CommandPrefix> Fortune Teller </CommandPrefix><Example> Will I find money </Example><Command Name="showMoney">
<Example> Will I find money </Example><ListenFor> [Will I find] {futureMoney} </ListenFor><Feedback> Showing {futureMoney} </Feedback><Navigate Target="/money.xaml"/>
</Command><PhraseList Label="futureMoney">
<Item> money </Item><Item> riches </Item><Item> gold </Item>
</PhraseList>
The Voice Command Definition (VCD) file
• This is the phrase the user
says to trigger the
command
• All of the Fortune Teller
commands start with this
phrase
<CommandPrefix> Fortune Teller </CommandPrefix><Example> Will I find money </Example><Command Name="showMoney">
<Example> Will I find money </Example><ListenFor> [Will I find] {futureMoney} </ListenFor><Feedback> Showing {futureMoney} </Feedback><Navigate Target="/money.xaml"/>
</Command><PhraseList Label="futureMoney">
<Item> money </Item><Item> riches </Item><Item> gold </Item>
</PhraseList>
The Voice Command Definition (VCD) file
• This is example text that
will be displayed by the
help for this app as an
example of the commands
the app supports
<CommandPrefix> Fortune Teller </CommandPrefix><Example> Will I find money </Example><Command Name="showMoney">
<Example> Will I find money </Example><ListenFor> [Will I find] {futureMoney} </ListenFor><Feedback> Showing {futureMoney} </Feedback><Navigate Target="/money.xaml"/>
</Command><PhraseList Label="futureMoney">
<Item> money </Item><Item> riches </Item><Item> gold </Item>
</PhraseList>
The Voice Command Definition (VCD) file
• This is the command
name
• This can be obtained from
the URL by the application
when it starts
<CommandPrefix> Fortune Teller </CommandPrefix><Example> Will I find money </Example><Command Name="showMoney">
<Example> Will I find money </Example><ListenFor> [Will I find] {futureMoney} </ListenFor><Feedback> Showing {futureMoney} </Feedback><Navigate Target="/money.xaml"/>
</Command><PhraseList Label="futureMoney">
<Item> money </Item><Item> riches </Item><Item> gold </Item>
</PhraseList>
The Voice Command Definition (VCD) file
• This is the example for this
specific command
<CommandPrefix> Fortune Teller </CommandPrefix><Example> Will I find money </Example><Command Name="showMoney">
<Example> Will I find money </Example><ListenFor> [Will I find] {futureMoney} </ListenFor><Feedback> Showing {futureMoney} </Feedback><Navigate Target="/money.xaml"/>
</Command><PhraseList Label="futureMoney">
<Item> money </Item><Item> riches </Item><Item> gold </Item>
</PhraseList>
The Voice Command Definition (VCD) file
• This is the trigger phrase for
this command
• It can be a sequence of
words
• The user must prefix this
sequence with the words
“Fortune Teller”
<CommandPrefix> Fortune Teller </CommandPrefix><Example> Will I find money </Example><Command Name="showMoney">
<Example> Will I find money </Example><ListenFor> [Will I find] {futureMoney} </ListenFor><Feedback> Showing {futureMoney} </Feedback><Navigate Target="/money.xaml"/>
</Command><PhraseList Label="futureMoney">
<Item> money </Item><Item> riches </Item><Item> gold </Item>
</PhraseList>
The Voice Command Definition (VCD) file
• This is the phraselist for the
command
• The user can say any of the
words in the phraselist to
match this command
• The application can
determine the phrase used
• The phraselist can be
changed by the application
dynamically
<CommandPrefix> Fortune Teller </CommandPrefix><Example> Will I find money </Example><Command Name="showMoney">
<Example> Will I find money </Example><ListenFor> [Will I find] {futureMoney} </ListenFor><Feedback> Showing {futureMoney} </Feedback><Navigate Target="/money.xaml"/>
</Command><PhraseList Label="futureMoney">
<Item> money </Item><Item> riches </Item><Item> gold </Item>
</PhraseList>
The Voice Command Definition (VCD) file
• This is the spoken feedback
from the command
• The feedback will insert the
phrase item used to
activate the command
<CommandPrefix> Fortune Teller </CommandPrefix><Example> Will I find money </Example><Command Name="showMoney">
<Example> Will I find money </Example><ListenFor> [Will I find] {futureMoney} </ListenFor><Feedback> Showing {futureMoney} </Feedback><Navigate Target="/money.xaml"/>
</Command><PhraseList Label="futureMoney">
<Item> money </Item><Item> riches </Item><Item> gold </Item>
</PhraseList>
The Voice Command Definition (VCD) file
• This is the url for the page
to be activated by the
command
• Commands can go to
different pages, or all go to
MainPage.xaml if required
<CommandPrefix> Fortune Teller </CommandPrefix><Example> Will I find money </Example><Command Name="showMoney">
<Example> Will I find money </Example><ListenFor> [Will I find] {futureMoney} </ListenFor><Feedback> Showing {futureMoney} </Feedback><Navigate Target="/money.xaml"/>
</Command><PhraseList Label="futureMoney">
<Item> money </Item><Item> riches </Item><Item> gold </Item>
</PhraseList>
The Voice Command Definition (VCD) file
• These are the phrases that
can be used at the end of
the command
• The application can modify
the phrase list of a
command dynamically
• It could give movie times
for films by name
Installing a Voice Command Definition (VCD) file
• The VCD file can be loaded from the application or from any URI
• In this case it is just a file that has been added to the project and marked as Content
• The VCD can also be changed by the application when it is running
• The voice commands for an application are loaded into the voice command service when
the application runs
• The application must run at least once to configure the voice commands
async void setupVoiceCommands(){
await VoiceCommandService.InstallCommandSetsFromFileAsync(new Uri("ms-appx:///VCDCommands.xml", UriKind.RelativeOrAbsolute));
}
Launching Your App With a Voice Command
• If the user now presses and holds the Windows button, and says:
Fortune Teller, Will I find gold?
the Phone displays “Showing gold”
• It then launches your app and navigates to the page associated with this command, which is
/Money.xaml
• The query string passed to the page looks like this:
"/?voiceCommandName=showMoney&futureMoney=gold&reco=Fortune%20Teller%Will%20I%20find%20gold"
Command
Name
Phaselist
Name
Recognized
phrase
Whole phrase as it
was recognized
Handling Voice Commands
• This code runs in the OnNavigatedTo method of a target page
• Can also check for the voice command phrase that was used
if (e.NavigationMode == System.Windows.Navigation.NavigationMode.New) {if (NavigationContext.QueryString.ContainsKey("voiceCommandName")) {
string command = NavigationContext.QueryString["voiceCommandName"];switch command) {
case "tellJoke":messageTextBlock.Text = "Insert really funny joke here";break;
// Add cases for other commands. default:
messageTextBlock.Text = "Sorry, what you said makes no sense.";break;
}}
}
Identifying phrases
• The navigation context can be queried to determine the phrase used to trigger the navigation
• In this case the program is selecting between the phrase used in the “riches” question
<PhraseList Label="futureMoney"><Item> money </Item><Item> riches </Item><Item> gold </Item>
</PhraseList>
string moneyPhrase = NavigationContext.QueryString["futureMoney"];
Demo 2:
Fortune Teller
Modifying the phrase list
• An application can modify a phrase list when it is running
• It cannot add new commands however
• This would allow a program to implement behaviours such as:
“Movie Planner tell me showings for Batman”
VoiceCommandSet fortuneVcs = VoiceCommandService.InstalledCommandSets["en-US"];
await fortuneVcs.UpdatePhraseListAsync("futureMoney", new string[] { "money", "cash", “millions", “piles of dough" });
Simple Speech Input
Recognizing Free Speech
• A Windows Phone application can recognize words and phrases
and pass them to your program
• From my experiments it seems quite reliable
• Note that a network connection is required for this feature if
you use the generic dictation grammar
• Your application can just use the speech string directly
• The standard “Listening” interface is displayed over
your application
Simple Speech Recognition
• The above method checks for a successful response
• By default the system uses the language settings on the Phone
SpeechRecognizerUI recoWithUI;
async private void ListenButton_Click(object sender, RoutedEventArgs e){
this.recoWithUI = new SpeechRecognizerUI();
SpeechRecognitionUIResult recoResult = await recoWithUI.RecognizeWithUIAsync();
if ( recoResult.ResultStatus == SpeechRecognitionUIStatus.Succeeded )MessageBox.Show(string.Format("You said {0}.",
recoResult.RecognitionResult.Text));}
Customizing Speech Recognition
• InitialSilenceTimeout
• The time that the speech recognizer will wait until it hears speech
• The default setting is 5 seconds
• BabbleTimeout
• The time that the speech recognizer will listen while it hears background noise
• The default setting is 0 seconds (the feature is not activated)
• EndSilenceTimeout
• The time interval during which the speech recognizer will wait before finalizing the
recognition operation
• The default setting is 150 milliseconds
Customizing Speech Recognition
• A program can also select whether or not the speech recognition echoes back the user
input and displays it in a message box
• The code above also sets timeout values
recoWithUI.Settings.ReadoutEnabled = false; // don't read the saying backrecoWithUI.Settings.ShowConfirmation = false; // don't show the confirmation
recoWithUI.Recognizer.Settings.InitialSilenceTimeout = TimeSpan.FromSeconds(6.0);recoWithUI.Recognizer.Settings.BabbleTimeout = TimeSpan.FromSeconds(4.0);recoWithUI.Recognizer.Settings.EndSilenceTimeout = TimeSpan.FromSeconds(1.2);
Handling Errors
• An application can bind to events which indicate problems with the audio input
• There is also an event fired when the state of the capture changes
recoWithUI.Recognizer.AudioProblemOccurred +=Recognizer_AudioProblemOccurred;recoWithUI.Recognizer.AudioCaptureStateChanged +=
Recognizer_AudioCaptureStateChanged;...
void Recognizer_AudioProblemOccurred(SpeechRecognizer sender, SpeechAudioProblemOccurredEventArgs args)
{MessageBox.Show("PLease speak more clearly");
}
Using Grammars
Grammars and Speech input
• The simple speech recognition we have seen so far uses the “Short Dictation” grammar
which just captures the text and returns it to the application
• You can add your own grammars that will structure the conversation between the user and
the application
• Grammars can be created using the Speech Recognition Grammar Specification (SRGS)
Version 1.0 and stored as XML files loaded when the application runs
• This is a little complex, but worth the effort if you want to create applications with rich
language interaction with the user
• If the application just needs to identify particular commands you can use a grammar list to
achieve this
• Custom grammars can be handled on the client without any network access
Using Grammar Lists
• To create a Grammar List an application defines an array of strings that form the words in
the list
• The Grammar can then be added to the recognizer and given a name
• Multiple grammar lists can be added to a grammar recognizer
• The recognizer will now resolve any of the words in the lists that have been supplied
string [] strengthNames = { "weak", "mild", "medium", "strong", "english"};
recoWithUI.Recognizer.Grammars.AddGrammarFromList("cheeseStrength", strengthNames);
Enabling and Disabling Grammar Lists
• An application can enable or disable particular grammars before a recognition action
• It is also possible to set relative weightings of grammar lists
• The text displayed as part of the listen operation can also be set, as shown above
recoWithUI.Settings.ListenText = "How strong do you like your cheese?";
recoWithUI.Recognizer.Grammars["cheeseStrength"].Enabled = true;
SpeechRecognitionUIResult recoResult = await recoWithUI.RecognizeWithUIAsync();
Determining the confidence in the result
• An application can determine the confidence that the speech system has in the result that
was obtained
• Result values are High, Medium, Low, Rejected
SpeechRecognitionUIResult recoResult = await recoWithUI.RecognizeWithUIAsync();
if ( recoResult.RecognitionResult.TextConfidence == SpeechRecognitionConfidence.High )
{// select cheese based on strength value
}
Matching Multiple Grammars
• If the spoken input matches multiple grammars a program can obtain a list of the
alternative results using recoResult.RecognitionResult.GetAlternatives
• The list is supplied in order of confidence
• The application can then determine the best fit from the context of the voice request
• This list is also provided if the request used a more complex grammar
var alternatives = recoResult.RecognitionResult.GetAlternates(3);
Profanity
• Words that are recognised as profanities are not displayed in the response from a
recognizer command
• The speech system will also not repeat them
• They are enclosed in <Profanity> </Profanity> when supplied to the program that
receives the speech data
Summary
• Applications in Windows Phone 8 can use speech generation and recognition to interact
with users
• Applications can produce speech output from text files which can be marked up with
Speech Synthesis Markup Language (SSML) to include sound files
• Applications can be started and provided with initial commands by registering a Voice
Command Definition File with the Windows Phone
• The commands can be picked up when a page is loaded, or the commands specify a
particular page to load
• An application can modify the phrase part of a command to change the
activation commands
• Applications can recognise speech using complex grammars or simple word lists
Summary and Next Steps…
Get Ready to Become a Windows Phone Developer
Download the SDK at dev.windowsphone.com
Explore the Microsoft samples and start building apps in Visual Studio
Learn More About Windows Phone Development via Official Microsoft Videos
Windows Phone 8 Jump Start Training: http://bit.ly/wp8jump
Windows Phone 8 Dev for Absolute Beginners: http://bit.ly/wp8devAB
Check Out Additional Learning Resources
Pluralsight WP Training: www.pluralsight.com/training/Courses#windows-phone
Nokia Developer: www.developer.nokia.com
Download Additional Resources & Become an Expert
Download the Windows Phone Toolkit: phone.codeplex.com
Nokia Developer Offers: http://bit.ly/nokiadevoffers
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Windows Phone Resources
• Windows Phone Developer Blog: blogs.windows.com/windows_phone/b/wpdev
• Windows Phone Consumer Blog: blogs.windows.com/windows_phone/b/windowsphone
• Nokia WP Wiki: www.developer.nokia.com/Community/Wiki/Category:Windows_Phone
• Nokia Dvlup Challenges & Rewards: www.dvlup.com
• Nokia Conversations Blog: http://conversations.nokia.com
• Microsoft App Studio: http://apps.windowsstore.com
• Nick Landry’s Blog: ActiveNick.net
• Windows Phone Developer Magazine (online): http://flip.it/95YFG
• GeekChamp (WP & Win8 dev): www.geekchamp.com
• Windows Phone Central (News): www.wpcentral.com
Thank You!
Slides and demos will be posted on SlideShare (see links below)
Let me know how you liked this session. Your feedback is important and appreciated.
Slideshare: www.slideshare.net/ActiveNick
Blog: www.ActiveNick.net
Twitter: @ActiveNick
Mobile Apps: www.bigbaldapps.com
LinkedIn: www.linkedin.com/in/activenick
Website: www.mobility42.com
Email: [email protected]