Clicks
Clicks are peculiar sounds used in some languages of Africa. They sound strange to Europeans and they prove to be relatively difficult to master when you try to learn them in an L2. You can learn about them from, for example, this presentation:
www.youtube.com/watch?v=a-fYVPWjcvs&list=PL7KCDYyP9MSiOxbWTK8x8uwyG1TW3NXMP
Download a sample of Nama Damara (Khoekhoe) language from:
www.phonetics.ucla.edu/vowels/chapter13/nama.html
Open the file in Praat in [View and Edit] window or in WaveSurfer in [Speech analysis] mode.
Listen to the the signal. Try to spot the clicks (which will not be difficult!) and find how they are represented in the spectrogram.
[Clicks are represented by vertical lines – they occupy almost the entire frequency range with high energy. But vertical lines can also represent any plosive consonants.]
Listen closer
Listen closely to the example. You will find that in the sequences of words, various types of clicks are used. How many of them can you distinguish by ear? To take a closer look at the clicks in the spectrogram, you will have to zoom in. Then you may notice some differences in their shape and surrounding.[The entire inventory of clicks in Nama reaches twenty items (!) while there are only eleven other consonants. Clicks are characterised by double articulation. They can be more sharp (dental or lateral) or affricated (alveolar or palatal), and each of these categories can be produced with five various accompaniments. For details, consult [Miller 2011].]
Record your own clicks
Once you tried to identify them by ear and then to view their spectrograms and to listen to them more closely, it is time to produce some clicks yourself. Record your clicks and listen to them. If you need more help, watch closely this video:
https://www.youtube.com/watch?v=31zzMb3U0iY&index=2&list=PL7KCDYyP9MSiOxbWTK8x8uwyG1TW3NXMP
[Sometimes clicks are produced by speakers of “non-click” languages as expressions of impatience, disgust, but also of astonishment or amazement. Probably you can easily produce at least some of them. It will be, however, much more difficult in the context of a regular utterance.]
More examples
Need more examples? You can find more videos, especially of Xhosa speakers, on the web.
You can also go the Interactive map and find the material on clicks in the language Taa
Reference
Miller, A. 2011. The Representation of Clicks. [In:] M. Oostendorp et al. (eds.), The Blackwell Companion to Phonology. Oxford: Blackwell.