/**
 * Metaphone Phonetic Algorithm
 * src/phonetic/Metaphone.ts
 *
 * @see https://en.wikipedia.org/wiki/Metaphone
 *
 * Metaphone is a phonetic algorithm for indexing words by their English pronunciation.
 * It encodes words into a string of consonant symbols, allowing for the comparison of
 * words based on their pronunciation rather than their spelling. Metaphone is more
 * accurate than Soundex for English and is widely used in search, spell-checking,
 * and fuzzy matching.
 *
 * This implementation uses a mapping and a comprehensive ruleset to efficiently
 * transform input words into their Metaphone code. The algorithm drops or transforms
 * letters according to context-sensitive rules, and only retains vowels at the start.
 *
 * @module Phonetic/Metaphone
 * @author Paul Köhler (komed3)
 * @license MIT
 */
import type { PhoneticOptions } from '../utils/Types';
import { Phonetic } from './Phonetic';
/**
 * Metaphone class extends the Phonetic class to implement the Metaphone phonetic algorithm.
 */
export declare class Metaphone extends Phonetic {
    protected static default: PhoneticOptions;
    /**
     * Constructor for the Metaphone class.
     *
     * Initializes the Metaphone phonetic algorithm with the mapping and options.
     *
     * @param {PhoneticOptions} [opt] - Options for the Metaphone phonetic algorithm
     */
    constructor(opt?: PhoneticOptions);
    /**
     * Generates the Metaphone code for a given word.
     *
     * @param {string} word - The input word to be converted into a Metaphone code
     * @returns {string} - The generated Metaphone code
     */
    protected encode(word: string): string;
    /**
     * Adjusts the Metaphone code by removing vowels except for the first letter.
     *
     * @param {string} code - The Metaphone code to be adjusted
     * @returns {string} - The adjusted Metaphone code
     */
    protected adjustCode(code: string): string;
}