Metaphone

The Metaphone class provides a phonetic simplification of Portuguese words, making it easier to implement approximate search functionality that is resilient to spelling variations and vowel differences.

info

Despite the name "Fonema" (phoneme), this class is not a faithful representation of Brazilian phonemes but rather a practical simplification for search purposes.

Basic Usage

use ByJG\WordProcess\Portuguese\Metaphone;

$metaphone = new Metaphone();
echo $metaphone->convert('brasília'); // Output: BRAZILIA
echo $metaphone->convert('brazilia'); // Output: BRAZILIA

Both variations produce the same output, making them searchable as equivalent terms.

Examples

Spelling Variations

Words with different spellings but similar pronunciation will generate the same phonetic representation:

$metaphone = new Metaphone();

// Different spellings, same output
echo $metaphone->convert('ambulancia'); // AMBULAMSSIA
echo $metaphone->convert('anbulancia'); // AMBULAMSSIA

// Case insensitive
echo $metaphone->convert('BALA');       // BALA
echo $metaphone->convert('bala');       // BALA

// Accent variations
echo $metaphone->convert('praça');      // PRASSA
echo $metaphone->convert('praças');     // PRASSAZ

Vowel Approximation

The algorithm normalizes vowels and common consonant variations:

$metaphone = new Metaphone();

echo $metaphone->convert('fome');       // FOME
echo $metaphone->convert('fama');       // FAMA

// Multiple repeated letters are simplified
echo $metaphone->convert('ffffffammmmmmmmmma'); // FAMA

Common Portuguese Patterns

The Metaphone handles common Portuguese phonetic patterns:

$metaphone = new Metaphone();

// Nasal sounds
echo $metaphone->convert('pão');        // PAUM
echo $metaphone->convert('pães');       // PAUM
echo $metaphone->convert('avião');      // AVIAUM
echo $metaphone->convert('aviões');     // AVIAUM

// S/Z variations
echo $metaphone->convert('mesa');       // MEZA
echo $metaphone->convert('casa');       // KAZA
echo $metaphone->convert('caça');       // KASSA

// CH/X sounds
echo $metaphone->convert('chave');      // XAVE
echo $metaphone->convert('chuva');      // XUVA
echo $metaphone->convert('mexe');       // MEXE

// Ç cedilla
echo $metaphone->convert('sessão');     // CESSAUM
echo $metaphone->convert('seção');      // CESSAUM
echo $metaphone->convert('facção');     // FAKSSAUM

How It Works

The Metaphone class applies a series of phonetic rules to simplify Portuguese words:

1. Pre-processing: Removes accents and normalizes repeated letters
2. Pattern matching: Applies Portuguese-specific phonetic rules
3. Output: Returns an uppercase simplified representation

The rules handle common Portuguese phonetic patterns including:

• Nasal sounds (ão, ães, ões → AUM)
• Consonant variations (c/ç/s/ss/z)
• Silent letters (h in most positions)
• Compound sounds (ch, lh, nh, qu)

Method Reference

convert(string $text): string

Converts a Portuguese word or phrase into its phonetic representation.

Parameters:

• $text (string): The text to convert (single word or phrase)

Returns:

• (string): The phonetic representation in uppercase

Example:

$metaphone = new Metaphone();
$result = $metaphone->convert('wellington');
echo $result; // Output: UELINTOM

getRules(): Rules

Returns the internal Rules object with all phonetic transformation rules. This is primarily for internal use but can be accessed if you need to customize the rules.

Returns:

• (Rules): The rules object containing all transformation patterns