Mr. Bird-here's to you my friend. May we meet again one day and whistle the 'Andy Griffith' theme together once more. Cockatiels are among the heartiest of parrot species and highly recommended for first time bird owners. As a general rule, they are loving, loyal, and even tempered. They are not prone to biting, but will 'strike' and hiss if feeling threatened or frightened.
Males are more prone to speaking than hens.
I have had some females speak limited phrases, however, but these are rare. Males will speak with a definite 'birdy' voice, but are usually easily understood. Both genders are generally whistlers, able to learn simple songs. Cockatiels originate in Australia. They are not limited to a specific region and habitate most of the continent.