Page 13 - The Modul of Psycholinguistics Studies_2

1. One acoustic aspect of the speech signal may cue different
linguistically relevant dimensions. For example, the

duration of a vowel in English can indicate whether or not
the vowel is stressed, or whether it is in a syllable closed by

a voiced or a voiceless consonant, and in some cases (like
American English /ɛ/ and /æ/) it can distinguish the
identity of vowels. Some experts even argue that duration

can help in distinguishing of what is traditionally called
short and long vowels in English.
2. One linguistic unit can be cued by several acoustic

properties. For example, in a classic experiment, Alvin
Liberman (1957) showed that the onset formant transitions

of /d/ differ depending on the following vowel (see Figure
1) but they are all interpreted as the phoneme /d/ by
listeners.

Linearity and the segmentation problem

Figure 2: A spectrogram
of the phrase "I owe
you". There are no
clearly distinguishable
boundaries between
speech sounds.

Although listeners perceive speech as a stream of discrete

units [citation needed] (phonemes, syllables, and words), this
linearity is difficult to see in the physical speech signal (see

Psycholinguistics | 13