Human Cognitive Neuropsychology
Chapter 6: recognising and understanding spoken words
Introduction
Auditory input lexicon (AIL): word store or lexicon for the recognition of spoken words
There are two views on how the AIL might work:
1. First the listener identifies phonemes in the acoustic wave, and then identifies the
word from its constituent phonemes.
2. The input to the auditory word recognition system is a low-level, relatively
unsegmented description of the speech waveform.
The first one is adopted as the working hypothesis.
We propose that the first stage of auditory word recognition is
performed by an auditory analysis system that attempts to
identify phonemes.
The results of this analysis are transmitted to the auditory input
lexicon where a match is sought.
If the match is a good one, the appropriate recognition unit in
the AIL will be activated.
This in turn activates the representation of the meaning of the
spoken word in the semantic system.
The arrow between the AIL and the SS is bidirectional. This
allows the SS to exert an influence upon the level of activity in the word-units which, in turn,
provides a mechanism whereby the semantic context in which a word occurs can affect its
ease of identification.
Pure word deafness
The pattern of symptoms
There are several cases reported of patients with ‘pure word deafness’. This involves
impaired speech perception in the context of good speech production, reading and writing,
and an intact perception of non-verbal environmental sounds.
Some patients have problems in the perception of melody or environmental sounds, but
these do not always accompany word deafness, thus can be ignored as possible causes.
Chapter 6: recognising and understanding spoken words
Introduction
Auditory input lexicon (AIL): word store or lexicon for the recognition of spoken words
There are two views on how the AIL might work:
1. First the listener identifies phonemes in the acoustic wave, and then identifies the
word from its constituent phonemes.
2. The input to the auditory word recognition system is a low-level, relatively
unsegmented description of the speech waveform.
The first one is adopted as the working hypothesis.
We propose that the first stage of auditory word recognition is
performed by an auditory analysis system that attempts to
identify phonemes.
The results of this analysis are transmitted to the auditory input
lexicon where a match is sought.
If the match is a good one, the appropriate recognition unit in
the AIL will be activated.
This in turn activates the representation of the meaning of the
spoken word in the semantic system.
The arrow between the AIL and the SS is bidirectional. This
allows the SS to exert an influence upon the level of activity in the word-units which, in turn,
provides a mechanism whereby the semantic context in which a word occurs can affect its
ease of identification.
Pure word deafness
The pattern of symptoms
There are several cases reported of patients with ‘pure word deafness’. This involves
impaired speech perception in the context of good speech production, reading and writing,
and an intact perception of non-verbal environmental sounds.
Some patients have problems in the perception of melody or environmental sounds, but
these do not always accompany word deafness, thus can be ignored as possible causes.
