Cockatiel

Although cockatiels are part of the parrot order, they are better at imitating whistles than speech. They may learn to whistle different tunes. Although they can learn words, the only understandable parts of the words are the inflections, while the consonants are not easily discernible. Their whistles and other mimicking sounds such as 'lip-smacking' and 'tutting' are almost perfect imitations of the sounds their owners make. Although some cockatiels do learn to repeat phrases, males are generally better at mimicry than females. It is said that some females cannot "talk" simple words and this is true, it mostly occurs in males. Cockatiel speech often comes out as a "whistle" when they do annunciate, the voice being soft in volume and difficult to make out. Cockatiels can mimic many sounds, such as the bleep of a car alarm, a ringing telephone, the sound of a zipper, the beeping of cell phones or microwaves, or the calls of other bird species such as blue jays or chickadees and loud weather like thunder. They can also mimic other pets such as dogs, occasionally barking back.

~Wikipedia