TheCodeBreakers
stops /bdg/ and they average twice the frequency of voiced stops in
sixteen widely varying languages surveyed by George K. Zipf. Similarly,
short vowels are markedly more frequent than long vowels or diphthongs.
In the same way, auditors of English, at least, seem to prefer sounds that
are easier to identify. Tests made with nonsense syllables show that
listeners seldom confuse consonants produced with the vocal organs
held in the same position but used in a different manner (such as
/ntrsdlz/), but usually fail to distinguish consonants produced with the
vocal organs used in the same manner but held in different positions
(such as /ptk/). In the first group (the alveolar consonants), the tongue
stays at the upper gum ridge but molds or interrupts the breath stream
in different ways. In the second group (the voiceless stops), all the
consonants block the breath
I
stream and explosively release it, but at different positions of the lips
and tongue
annaabi.ee 
