This » PECL extension is not bundled with PHP.
In order to use these functions you must compile PHP with Hyperwave support by using the --with-hyperwave[=DIR] configure option.
Windows users will enable php_hyperwave.dll inside of php.ini in order to use these functions. The DLL for this PECL extension may be downloaded from either the » PHP Downloads page or from » http://pecl4win.php.net/