1 page.title=Speech Input 2 parent.title=Articles 3 parent.link=../browser.html?tag=article 4 @jd:body 5 6 <p> People love their mobile phones because they can stay in touch wherever they 7 are. That means not just talking, but e-mailing, texting, microblogging, and so 8 on. </p> 9 10 <p>Speech input adds another dimension to staying in touch. 11 Google's Voice Search application, which is pre-installed on many Android devices 12 and available in Android Market, provides powerful features like "search by voice" 13 and Voice Actions like "Navigate to." Further 14 enhancing the voice experience, Android 2.1 introduces a <a 15 href="http://www.youtube.com/watch?v=laOlkD8LmZw"> 16 voice-enabled keyboard</a>, which makes it even easier 17 to stay connected. Now you can dictate your message instead of typing it. Just 18 tap the new microphone button on the keyboard, and you can speak in just about 19 any context in which you would normally type. </p> 20 21 <p> We believe speech can 22 fundamentally change the mobile experience. We would like to invite every 23 Android application developer to consider integrating speech input capabilities 24 via the Android SDK. One of our favorite apps in the Market that integrates 25 speech input is <a href="http://www.handcent.com/">Handcent SMS</a>, 26 because you can dictate a reply to any SMS with a 27 quick tap on the SMS popup window. Here is Speech input integrated into 28 Handcent SMS:</p> 29 30 <img src="images/speech-input.png"/> 31 32 33 <p> The Android SDK makes it easy to integrate speech input directly into your 34 own application. Just copy and paste from this <a 35 href="{@docRoot}resources/samples/ApiDemos/src/com/example/android/apis/app/VoiceRecognition.html">sample 36 application</a> to get 37 started. The sample application first verifies that the target device is able 38 to recognize speech input:</p> 39 <pre> 40 // Check to see if a recognition activity is present 41 PackageManager pm = getPackageManager(); 42 List<ResolveInfo> activities = pm.queryIntentActivities( 43 new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH), 0); 44 if (activities.size() != 0) { 45 speakButton.setOnClickListener(this); 46 } else { 47 speakButton.setEnabled(false); 48 speakButton.setText("Recognizer not present"); 49 } 50 </pre> 51 <p> 52 The sample application then uses {@link 53 android.app.Activity#startActivityForResult(android.content.Intent, int) 54 startActivityForResult()} to broadcast an intent that requests voice 55 recognition, including an extra parameter that specifies one of two language 56 models. The voice recognition application that handles the intent processes the 57 voice input, then passes the recognized string back to your application by 58 calling the {@link android.app.Activity#onActivityResult(int, int, 59 android.content.Intent) onActivityResult()} callback. </p> 60 61 62 <p>Android is an open platform, so your application can potentially make 63 use of any speech recognition service on the device that's registered to receive 64 a {@link android.speech.RecognizerIntent}. Google's Voice Search application, 65 which is pre-installed on 66 many Android devices, responds to a <em>RecognizerIntent</em> by displaying the 67 "Speak 68 now" dialog and streaming audio to Google's servers -- the same servers used 69 when a user taps the microphone button on the search widget or the voice-enabled 70 keyboard. You can check whether Voice Search is installed in 71 <strong>Settings > Applications > Manage applications</strong>. </p> 72 73 <p> One important tip: for speech input to be as accurate as possible, it's 74 helpful to have an idea of what words are likely to be spoken. While a message 75 like "Mom, I'm writing you this message with my voice!" might be appropriate for 76 an email or SMS message, you're probably more likely to say something like 77 "weather in Mountain View" if you're using Google Search. You can make sure your 78 users have the best experience possible by requesting the appropriate 79 <em>language model:</em> {@link 80 android.speech.RecognizerIntent#LANGUAGE_MODEL_FREE_FORM free_form} for 81 dictation, or {@link android.speech.RecognizerIntent#LANGUAGE_MODEL_WEB_SEARCH 82 web_search} for shorter, search-like phrases. We developed the "free form" 83 model to improve dictation accuracy for the voice keyboard, 84 while the "web search" model is used when users want to search by voice. </p> 85 86 <p> Google's servers support many languages for voice input, with more arriving 87 regularly. You can use the 88 {@link android.speech.RecognizerIntent#ACTION_GET_LANGUAGE_DETAILS} 89 broadcast intent to query for the list of supported languages. 90 The web search model is available for all languages, while the free-form model 91 may not be optimized for all languages. As we work hard to support more models in 92 more languages, and to improve the accuracy of the speech recognition technology 93 we use in our products, Android developers who integrate speech capabilities 94 directly into their applications can reap the benefits as well. </p> 95
