If you want to make the terminal beep on a PHP CLI application without needing the ncurses library, use the following code:
(PHP 4 >= 4.0.7, PHP 5 < 5.3.0, PECL ncurses >= 1.0.0)
ncurses_beep — Let the terminal beep
This function is EXPERIMENTAL. The behaviour of this function, its name, and surrounding documentation may change without notice in a future release of PHP. This function should be used at your own risk.
ncurses_beep() sends an audible alert (bell) and if its not possible flashes the screen.