Speech and Braille

NVDA provides comprehensive support for both speech synthesis and braille displays, enabling multiple ways to access computer content.

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Speech Synthesizer Support

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Built-in Speech: eSpeak NG

NVDA includes eSpeak NG, a free, open-source, multilingual speech synthesizer. Features:

• Supports over 80 languages
• No additional downloads required
• Lightweight and responsive
• Multiple voice variants available
• Adjustable speech parameters

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Changing Synthesizers

Supported synthesizers include:

• eSpeak NG (built-in)
• Microsoft Speech API version 4 (SAPI 4)
• Microsoft Speech API version 5 (SAPI 5)
• Microsoft OneCore voices (Windows 10/11)
• Windows Speech Platform
• Third-party synthesizers via add-ons

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Speech Settings

Access speech settings: Press NVDA+Control+V

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Voice Selection

Voice

Choose from available voices for your current synthesizer. Each voice has distinct characteristics:

• Microsoft voices: Natural-sounding, available in Windows
• eSpeak NG voices: Fast, responsive, many languages
• Third-party voices: Premium voices with advanced features

Use arrow keys to preview voices as you navigate the list.

Variant

For eSpeak NG, select voice variants:

• Male variants
• Female variants
• Specialized variants (different timbres)

Variants provide slight modifications to the base voice characteristics.

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Speech Parameters

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Capital Letters Announcement

NVDA offers three ways to indicate capital letters:

Pitch Change

Capital pitch change percentage: -100 to +100NVDA raises or lowers pitch for capital letters. Positive values raise pitch, negative values lower it. Set to 0 to disable.Example: Setting 30 raises pitch by 30% for capitals.

Say Cap Before

Say “cap” before capitals: CheckboxNVDA speaks the word “cap” before each capital letter when spelling.Best for: Individual character spelling

Beep for Capitals

Beep for capitals: CheckboxNVDA plays a short beep when encountering capital letters.Best for: Quick scanning of text

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Punctuation and Symbol Level

Quick change: Press NVDA+P

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Language Switching

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Automatic Language Switching

When enabled, NVDA automatically switches to the appropriate synthesizer language when reading text that specifies its language. Settings:

• Automatic Language switching: Enable/disable language detection
• Automatic Dialect switching: Switch between dialects (e.g., US/UK English)
• Report language changes: Announce when language changes

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Speech Modes

Cycle through modes with NVDA+S:

Talk Mode (Default)

NVDA speaks normally:

• Announces screen changes
• Reports focus movements
• Reads text as you navigate
• Provides notifications

Use when: Normal screen reader operation

On-demand Mode

NVDA only speaks when you explicitly request information:

• No automatic announcements
• Commands like NVDA+T still work
• Silent focus movements

Use when:

• Recording audio
• In meetings or calls
• You need constant focus without interruption

Off Mode

NVDA doesn’t speak but remains responsive:

• Completely silent
• All commands still function
• Braille continues working

Use when: Using braille exclusively

Beeps Mode

NVDA replaces speech with beeps:

• Short beeps for output
• Indicates activity without speech
• Useful for monitoring scrolling content

Use when: You need to know something is happening but don’t need details

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Synth Settings Ring

Quickly adjust settings without opening menus:

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Braille Support

NVDA supports over 100 braille displays and uses LibLouis for translation.

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Setting Up a Braille Display

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Braille Display Types

Supported displays include:

• Freedom Scientific (Focus, PAC Mate)
• Humanware (Brailliant, BrailleNote)
• HIMS (Braille Sense, Smart Beetle)
• Handy Tech displays
• Papenmeier displays
• Baum/VarioConnect displays
• Alva displays
• Eurobraille displays
• And many more…

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Braille Tables

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Output Table

Determines how text is converted to braille: Types:

• Grade 1 (Uncontracted): Letter-for-letter translation
• Grade 2 (Contracted): Shortened forms using contractions
• Computer braille: 8-dot display of characters
• Language-specific tables: Optimized for specific languages

Setting: Automatic selects based on NVDA’s current language

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Input Table

Determines how braille keyboard input is interpreted:

• Must match your expected input style
• Only relevant for displays with braille keyboards
• Supports multiple grade levels

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Braille Mode

Toggle: NVDA+Alt+T

Follow Cursors

Braille displays what’s at the cursor:

• System focus/caret content
• Navigator object/review cursor content
• Follows tether setting

Best for: Standard screen reader use

Display Speech Output

Braille shows what NVDA speaks:

• Mirrors speech output
• Useful for demonstration
• Helpful when speech is interrupted

Best for: Teaching, presentations, noisy environments

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Braille Tethering

Quick change: NVDA+Control+T Controls what braille follows:

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Braille Cursor Settings

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Show Cursor

Enable/disable the braille cursor (dots 7 and 8). Options:

• Show cursor (default)
• Hide cursor

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Blink Cursor

Make the braille cursor blink for visibility. Settings:

• Blink rate in milliseconds
• Blinking on/off

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Cursor Shape

Customize cursor appearance:

• Focus cursor: Shape when braille follows focus
• Review cursor: Shape when braille follows review

Dot patterns: Any combination of dots 1-8

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Braille Messages

Control how NVDA displays temporary messages: Show messages:

• Use timeout (disappear automatically)
• No timeout (stay until dismissed)
• No messages (never show on braille)

Message timeout: Set duration in seconds

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Advanced Braille Features

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Expand to Computer Braille

The word under the cursor displays in 8-dot computer braille for precise character inspection.

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Read by Paragraph

When enabled, braille pans by paragraph instead of line:

• Reduces frequent panning
• Better context when reading
• More natural reading flow

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Move System Caret When Routing

Controls whether routing keys move the system cursor:

• Never: Routing only moves review cursor
• Always: Routing moves both review and system cursor
• Only when tethered automatically: Conditional behavior

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Braille Input

For displays with braille keyboards:

Standard Braille Input

Type using the Perkins-style keyboard:

• Dots 1-6 for standard braille
• Dot 7 chord for uppercase
• Dot 8 for special functions
• Space bar confirms entry

Input table determines interpretation.

Common Chords

Special character combinations:

• Backspace: Dot 7
• Enter: Dot 8
• Tab: Dots 4-5
• Escape: Dots 1-5
• Arrow keys: Various dot combinations

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Combining Speech and Braille

Use both simultaneously for optimal access:

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Benefits of Dual Output

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Synchronized Navigation

Speech and braille stay synchronized:

• Navigate with keyboard: Both update
• Use routing keys: Speech announces position
• Braille pans: Speech reads new content
• Change focus: Braille follows immediately

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Audio Enhancements

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Audio Ducking

NVDA can lower volume of other applications when speaking: Settings:

• Duck audio (enabled by default on Windows 8+)
• Duck when outputting speech and sounds
• Always duck audio

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Audio Output Device

Choose which device NVDA uses for audio:

• Default system device
• Specific sound card
• Separate device for NVDA

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WASAPI

Windows Audio Session API improves performance: Benefits:

• Better responsiveness
• Improved timing
• Lower latency

Note: Only available for SAPI 5 voices

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Customizing Pronunciation

Adjust how NVDA speaks symbols and words:

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Symbol Pronunciation

Access: NVDA Menu > Preferences > Punctuation/Symbol Pronunciation Examples:

• Speak ”@” as “at” instead of “at sign”
• Pronounce ”#” as “number” instead of “pound”
• Silence certain symbols entirely

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Speech Dictionaries

Create custom word pronunciations: Three dictionary types:

Default Dictionary

Applies to all voices:

• Company names
• Technical terms
• Acronyms

Use for: Universal corrections

Voice Dictionary

Applies to current synthesizer voice:

• Voice-specific corrections
• Per-voice preferences

Use for: Issues with specific voices

Temporary Dictionary

Active until NVDA restarts:

• Quick fixes
• Testing pronunciations

Use for: Temporary adjustments

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Dictionary Patterns

Pattern types:

• Anywhere: Matches within words
• Whole word: Matches complete words only
• Regular expression: Advanced pattern matching

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Troubleshooting

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Speech Issues

Speech Stops Working

Solutions:

1. Press Control to stop speech, then try again
2. Press NVDA+Control+S and reselect synthesizer
3. Check speech mode with NVDA+S
4. Restart NVDA

Wrong Language

Solutions:

1. Check automatic language switching setting
2. Verify document language metadata
3. Manually select voice in correct language
4. Disable automatic switching if problematic

Pronunciation Problems

Solutions:

1. Add entry to speech dictionary
2. Adjust symbol pronunciation
3. Try different voice/synthesizer
4. Disable “Trust voice’s language” setting

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Braille Issues

Display Not Detected

Solutions:

1. Verify USB/Bluetooth connection
2. Try manual display selection
3. Install display drivers if required
4. Check display power and batteries
5. Restart NVDA after connecting

Wrong Braille Output

Solutions:

1. Verify output table selection
2. Check language setting
3. Ensure correct grade (contracted/uncontracted)
4. Try computer braille for debugging

Input Not Working

Solutions:

1. Verify display has input capability
2. Check input table setting
3. Ensure braille keyboard is active on display
4. Test with simple characters first