Vowels,
like consonants, can be produced with a raised velum that prevents the air from
escaping through the nose, or with a lower velum that permits air to pass
through the nasal passage. When the nasal passage is blocked, oral vowels are
produced; when the velum is lowered, nasalised vowels are produced. In English
nasalised vowels occur only before nasal consonants, and oral vowels occur only
before oral consonants. In fast colloquial speech, some speaker ‘drop’ the
nasal consonant when it occur before voiceless stops, as in hint or camp,
leaving just the nasalised vowel, but the word originates with a nasal
consonant. The words bean, ban, boon; beam, bam, boom; and bing, bang, bong are
example of words that contain nasalised vowels. The word in pat seems
particulary susceptible to nasalisation, especially when it is both preceded
and followed by nasal consonants as in man. A diacritic mark [~] placed over
indicates nasalisation, as in [mãen]. In English, this would
only be necessary for a highly detailed transcription, sometimes referred to as
a narrow phonetic transcription.
In language such as French, Polish, and Portuguese,
nasalised vowels may occur when no nasal consonant is adjacent. In French, for
example, the word meaning ‘year’ is an [ã]
and the word for ‘sound’ is son [sõ]. The n in the spelling
is not pronounced but indicates in these words that the vowels are nasalised.
A distinction between the term nasal and nasalised is
usually maintained by phoneticians. Nasal sounds are those produced with the
velum lowered and
The conventional way of transcribing these two final diphthongs, [aʊ]
and [oʊ], does not reflect very well their actual pronunciation (which migh be
more accurately transcribed as [æɒ] and [ʌu] respectively). The transcription
is a traditional one, based on earlier British practice, and is still the usual
convention in Australia. We have retained for this reason.
The
oral cavity blocked, so that air flows out only through the nose. In English,
these sounds are the consonants [m, n, ŋ]. Nasalised sounds are those with the
velum lowered and the mouth unblocked; air flows out through both mouth and
nose.
