<?php
require_once 'vendor/autoload.php';
use Google\Cloud\Speech\V1\RecognitionConfig\AudioEncoding;
use Google\Cloud\Speech\V1\RecognitionConfig;
use Google\Cloud\Speech\V1\StreamingRecognitionConfig;

$recognitionConfig = new RecognitionConfig();
$recognitionConfig->setEncoding(AudioEncoding::FLAC);
$recognitionConfig->setSampleRateHertz(44100);
$recognitionConfig->setLanguageCode('en-US');
$config = new StreamingRecognitionConfig();
$config->setConfig($recognitionConfig);

$audioResource = fopen('path/to/audio.flac', 'r');

$responses = $speechClient->recognizeAudioStream($config, $audioResource);

foreach ($responses as $element) {
    // doSomethingWith($element);
}