How to increase accuracy in Speech Recognition

How to improve accuracy with Dragon NaturallySpeaking Recorder Edition

Answer ID 5762   |    Published 06/09/2009 12:00 AM   |    Updated 04/16/2010 04:34 PM
How to improve accuracy with Dragon NaturallySpeaking Recorder Edition Information:
There are multiple ways to improve accuracy when using Dragon NaturallySpeaking Recorder Edition:
  • Running the Acoustic and Language Model Optimizer.
  • Performing corrections.
  • Analyzing e-mail.

Method 1: Performing corrections
After the user transcribes an audio file, the user should correct any words that were not recognized properly. With the Recorder Edition, it is not possible to correct words by voice.
To perform corrections:
  1. Open a digital recorder user profile.
  2. Perform a transcription of an audio file by using the "Transcribe" button on the DragonBar.
  3. Using the mouse, highlight the text that needs to be corrected.
  4. Click the "Correction" button on the DragonBar or press the Correction Hotkey (the "minus" key on the numberic keypad, by default) to display the Correction dialog.
  5. If the correct word is displayed in the Correction dialog, select that word to make the correction.
    Note: The user can click the "Playback" button at this time to verify what was originally dictated.
  6. If the correct word is not displayed in the Correction dialog, click the “Spell That…” option and type out the correct word in the Spell dialog.
  7. Press the "Enter" key or click “OK” to make the correction.
  8. Correcting in this manner will adapt the user's voice files, leading to continuously improving accuracy.
Method 2: Analyzing e-mail
Use the Increase Accuracy from E-mail tool to add the names of people the user has sent e-mail to into the Dragon vocabulary. The user has the option to edit these names and can also have Dragon scan the contents of the user's sent e-mail and add it to the language model.
To analyze e-mail:
  1. Open a digital recorder user profile.
  2. Click "Tools > Accuracy Center".
  3. Click the "Increase accuracy from e-mail" link.
  4. The Increase Accuracy from E-mail wizard opens. Click the "Next" button.
  5. Select the e-mail source to be used:
    • Lotus Notes
    • Microsoft Outlook
    • Outlook Express
  6. Select one or both of the following options:
    • Add contact names from e-mail to the vocabulary
    • Improve my speech files from my e-mail writing style
  7. Select one of the following options:
    • Consider e-mail written since my last scan
    • Consider all e-mail
  8. Click the "Next" button to start analyzing e-mail.
Method 3: The Acoustic and Language Model Optimizer
Before running the Acoustic and Language Model Optimizer, make sure the "Store corrections in archive" option is enabled under "Tools > Options > Data tab". If this option is not enabled, the user may see a message that there is not enough data for the Acoustic and Language Model Optimizer to process.
To run the Acoustic and Language Model Optimizer:
  1. Open a digital recorder user profile.
  2. Click "Tools > Accuracy Center".
  3. Click the "Run the Acoustic and Language Model Optimizer" link.
  4. Enable the "Perform Acoustic Optimization" and/or the "Perform Language Model Optimization" options.
    • Select "Perform Acoustic Optimization" to update the user profile with accumulated acoustic data from any corrections made by the user.
    • Select "Perform Language Model Optimization" to update the language model. The language model contains statistical information that predicts which words are most likely to occur in the context of the user’s speech.
  5. Click the "Go" button to begin the optimization.
  6. The Acoustic and Language Model Optimizer dialog box will display the amount of time to finish adapting the user files and display a progress bar to indicate how much of the job is complete. It generally takes as long to adapt the user files as the amount of data stored. For example, if there is 30 minutes of acoustic data stored, the processing time will be approximately 30 minutes.
  7. Once the optimization has completed, save the user profile by clicking "NaturallySpeaking > Save User Files".
General tips on increasing accuracy:

  • If using the digital recording device's built-in microphone, always hold the device at the same distance from the user's mouth. Some users rest the device on their jaw for the most consistent results.
  • Consider connecting a headset microphone to the digital recording device rather than using the built-in microphone. Using a high-quality external microphone is likely to produce better quality recordings.
  • Adjust the Speed vs. Accuracy setting under "Tools > Options > Miscellaneous tab". The Speed vs. Accuracy setting adjusts the number of words and phrases that the program examines in order to find a word match. The more words that are examined, the greater the possibility of an accurate match. However, this comes at the expense of using more memory and taking a longer time to recognize the user's speech. The user can adjust the Speed vs. Accuracy slider to influence the performance of Dragon. As a general rule, the user should move the slider farther to the right on faster machines than on slower ones.