Make a hopefully pronounceable word based on vowel, constant patterns. Patterns are pregenerated from analyzing dictionary files.

makeStatistics.php

<?php
// A.B. Carroll, <[email protected]>
// "Do whatever the fuck you want license"

// Generates a 'statistics chunk' for use in pronounceable word generation
// It's a one-time generation, so it doesn't need to be fast.

$file = file('/usr/share/dict/american-english');
$patterns = [];


// Initial pass
$vowels = 'aeiou';
$vowels = str_split($vowels);
foreach($file as $word) {
    $word = trim($word);
    if(preg_match('/^[A-Za-z]+$/', $word)) {
        //echo "Regular word: $word\n";
        $pattern = '';

        $word = str_split($word);
        foreach($word as $letter) {
            if(in_array($letter, $vowels)) {
                $pattern .= 'v';
            } else {
                $pattern .= 'c';
            }
        }

        if(!isset($patterns[strlen($pattern)])) {
            $patterns[strlen($pattern)] = [];
        }

        if(!isset($patterns[strlen($pattern)][$pattern])) {
            $patterns[strlen($pattern)][$pattern] = 0;
        }
        $patterns[strlen($pattern)][$pattern]++;
    }
}

// Prune, sort, re-key
$sortedPatterns = [];
ksort($patterns, SORT_NUMERIC);
foreach($patterns as $length => $iPatterns) {

    asort($iPatterns, SORT_NUMERIC);
    $iPatterns = array_reverse(($iPatterns));
    $total = array_sum($iPatterns);
    foreach($iPatterns as $pattern => $count) {

        $percentage = (int) round(($count / $total) * 100);
        if($percentage > 2 && strlen($pattern) <= 10) {
            // echo "$length => $pattern => $count ($percentage%)\n";

            if(!isset($sortedPatterns[strlen($pattern)])) {
                $sortedPatterns[strlen($pattern)] = [];
            }

            $sortedPatterns[strlen($pattern)][$percentage] = $pattern;
        }
    }
}

echo "Your statistics chunk:\n\n";
echo json_encode($sortedPatterns);

pronouncableWord.php

<?php
// A.B. Carroll, <[email protected]>
// "Do whatever the fuck you want license"

// Generates a pronouncable word based on pregenerated vowel,constant 
// statistical data

// Sshh.. No words.. Only code now...
function pronounceableWord($length) {
    $patternData = '{"1":{"90":"c","10":"v"},"2":{"51":"cc","35":"cv","15"' .
        ':"vc"},"3":{"64":"cvc","9":"cvv","7":"ccv","4":"vcv"},"4":{"39":"' .
        'cvcc","20":"cvcv","14":"ccvc","3":"vcvc"},"5":{"24":"cvcvc","17":' .
        '"cvccc","13":"ccvcc","9":"cvvcc","8":"cvccv","5":"ccvvc","3":"cvv' .
        'cv"},"6":{"27":"cvccvc","12":"cvcvcc","7":"ccvcvc","6":"cvvcvc","' .
        '5":"cvcvvc","3":"ccvvcc"},"7":{"20":"cvccvcc","9":"ccvccvc","8":"' .
        'cvcvcvc","7":"cvccvvc","4":"ccvcvcc","3":"ccvvcvc"},"8":{"9":"cvc' .
        'cvcvc","8":"ccvccvcc","7":"cvcvcvcc","6":"cvcccvcc","5":"cvcvccvc' .
        '","4":"cvccvccc","3":"cvcvcvcv"},"9":{"9":"cvccvcvcc","6":"cvccvc' .
        'cvc","5":"cvcvccvcc","4":"cvcvcvcvc","3":"ccvcccvcc"},"10":{"6":"' .
        'cvccvccvcc","4":"cvcvcvcvcc","3":"cvcvccvcvc"}}';
    
    $patternData = json_decode($patternData, true);
    if(isset($patternData[$length])) {
        $patternData = $patternData[$length];
        $maxProbability = array_sum(array_keys($patternData));
        $accumulatedProbability = 0;
        $rand = mt_rand(0, $maxProbability); // the magic deciding number
        $selectedPattern = '';
        foreach($patternData as $probability => $pattern) {
            $actualProbability = $probability + $accumulatedProbability;
            $accumulatedProbability = $probability + $accumulatedProbability;
            if($rand < $actualProbability) {
                $selectedPattern = $pattern;
                break;
            }
        }
        $selectedPattern = str_split($selectedPattern);
        $vowelConstants = [
            'v' => str_split('aeiou'),
            'c' => str_split('bcdfghklmnpqrstvwxyz')
        ];
        $generatedWord = '';
        foreach($selectedPattern as $letter) {
            $vc = $vowelConstants[$letter];
            $generatedWord .= $vc[array_rand($vc)];
        }
        return $generatedWord;
    } else {
        throw new \RuntimeException("Length of '$length' isn't supported by" .
            "the pattern data provided.");
    }
}

echo "And the winner is... ";
echo pronounceableWord(5);
echo "\n\n";