Voice formatting plan

Format LLM output for natural-sounding speech

Overview

Voice formatting automatically transforms raw text from your language model (LLM) into a format that sounds natural when spoken by a text-to-speech (TTS) provider. This process—called Voice Input Formatted—is enabled by default for all assistants.

Formatting helps with things like:

Expanding numbers and currency (e.g., $42.50 → “forty two dollars and fifty cents”)
Expanding abbreviations (e.g., ST → “STREET”)
Spacing out phone numbers (e.g., 123-456-7890 → “1 2 3 4 5 6 7 8 9 0”)

You can turn off formatting if you want the TTS to read the raw LLM output.

How voice input formatting works

When enabled, the formatter runs a series of transformations on your text, each handled by a specific function. Here’s the order and what each function does:

Step	Function Name	Description	Before	After	Default	Precedence
1	`removeAngleBracketContent`	Removes anything within `<...>`, except for `<break>`, `<spell>`, or double angle brackets `<< >>`.	`Hello <tag> world`	`Hello world`	✅	-
2	`removeMarkdownSymbols`	Removes markdown symbols like `_`, `, and `~`. Asterisks (`*`) are preserved in this step.	`Wanted to say hi`	`Wanted to say hi`	✅	0
3	`removePhrasesInAsterisks`	Removes text surrounded by single or double asterisks.	`Wanted to say hi`	`to say`	❌	0
4	`replaceNewLinesWithPeriods`	Converts new lines (`\n`) to periods for smoother speech.	`Hello world\n to say\nWe have NASA`	`Hello world . to say . We have NASA`	✅	0
5	`replaceColonsWithPeriods`	Replaces `:` with `.` for better phrasing.	`price: $42.50`	`price. $42.50`	✅	0
6	`formatAcronyms`	Converts known acronyms to lowercase (e.g., NASA → nasa) or spaces out unknown all-caps words unless they contain vowels.	`NASA and .NET`	`nasa and .net`	✅	0
7	`formatDollarAmounts`	Converts currency amounts to spoken words.	`$42.50`	`forty two dollars and fifty cents`	✅	0
8	`formatEmails`	Replaces `@` with “at” and `.` with “dot” in emails.	`JOHN.DOE@example.COM`	`JOHN dot DOE at example dot COM`	✅	0
9	`formatDates`	Converts date strings into spoken date format.	`2023 05 10`	`Wednesday, May 10, 2023`	✅	0
10	`formatTimes`	Expands or simplifies time expressions.	`14:00`	`14`	✅	0
11	`formatDistances`, `formatUnits`, `formatPercentages`, `formatPhoneNumbers`	Converts units, distances, percentages, and phone numbers into spoken words.	`5km`, `43 lb`, `50%`, `123-456-7890`	`5 kilometers`, `forty three pounds`, `50 percent`, `1 2 3 4 5 6 7 8 9 0`	✅	0
12	`formatNumbers`	Formats general numbers: years read as digits, large numbers spelled out, negative and decimal numbers clarified.	`-9`, `2.5`, `2023`	`minus nine`, `two point five`, `2023`	✅	0
13	`removeAsterisks`	Removes all asterisk characters from the text.	`Bold and italic`	`Bold and italic`	✅	1
14	`Applying Replacements`	Applies user-defined final replacements like expanding street abbreviations.	`320 ST 21 RD`	`320 STREET 21 ROAD`	✅	-

Customizing the formatting plan

You can control some aspects of formatting:

Enabled

Formatting is on by default. To disable, set:

1 voice.chunkPlan.formatPlan.enabled = false

Number-to-digits cutoff

Controls when numbers are read as digits instead of words.

Default: 2025 (current year)
Example: With a cutoff of 2025, numbers above this are read as digits.
To spell out larger numbers, set the cutoff higher (e.g., 300000).

Replacements

Add exact or regex-based substitutions to customize output.

Example 1: Replace hello with hi:

1 { type: 'exact', key: 'hello', value: 'hi' }

Example 2: Replace words matching a pattern:

1 { type: 'regex', regex: '\b[a-zA-Z]{5}\b', value: 'hi' }

Currently, only replacements and the number-to-digits cutoff are customizable. Other options are not exposed.

Turning formatting off

To disable all formatting and use raw LLM output, set either of these to false:

1 voice.chunkPlan.enabled = false
2 // or
3 voice.chunkPlan.formatPlan.enabled = false

Summary

Voice input formatting improves clarity and naturalness for TTS.
Each transformation step targets a specific pattern for better speech output.
You can customize or disable formatting as needed.

1	voice.chunkPlan.enabled = false
2	// or
3	voice.chunkPlan.formatPlan.enabled = false