Patterns of phonological disability in Cantonese-speaking children in Hong Kong.

Tone, vowel and consonant production are described for a large group of Cantonese-speaking children assessed in speech and language therapy clinics in Hong Kong. The patterns of disability follow predictions made on the basis of work on normal phonological development in Cantonese, and on psychoacoustic factors in acquisition: consonants account for more disability than vowels, and tones are least problematic. Possible articulatory and auditory contributions to explanation of the observed patterns are discussed.

Real-time speech pattern element displays for interactive therapy.

New developments are presented and discussed for the interactive display and separate measurement of frication and nasality in addition to voice quality. Different clinical problems require different therapeutic and quantitative approaches and these are ideally supported by appropriate combinations of speech pattern elements. Particular use has been made of the laryngograph signal in order to solve the problems of analysis and so that the displays can be given both a sense of immediacy and be highly accurate.

Laryngograph: speech pattern element tools for therapy, training and assessment.

The clinically based, real-time analysis of speech into physically definable elements, which are of direct perceptual and productive importance, has become more readily possible in recent years as the result of microprocessor developments. The combination of the acoustic signal of speech derived from a microphone together with the accompanying Laryngograph signal provides the basis for a highly reliable set of facilities. The paper describes methods and results for the analysis of voice, frication and timbre for both quantitative analysis and teaching and therapy using interactive visual displays. A brief discussion is given of links to work in stroboscopy, electropalatography and the associated use of additional sensors. Finally reference is made to a complete clinical work station combining these different facilities together with the quantitative analytical procedures of the speech pattern audiometer.

Speech pattern audiometry for clinical use.

A new PC-based speech perception testing system ('speech pattern audiometer') is described which aims to provide a simple and efficient clinical tool to assess patients' ability to make use of the acoustic speech pattern information which is fundamental to speech perception. The speech pattern audiometer is likely to find its main application in audiology and speech and language therapy clinics with those who are deaf or who have developmental or acquired speech-perceptual disorders. This system constitutes a module of a complete speech and hearing assessment and teaching/therapy workstation.

Development of phonetic labeling in hearing-impaired children.

The development of labeling ability of an unselected group of 16 severely to profoundly hearing-impaired children was assessed over a period of 4 years, using synthetic speech pattern tests of increasing acoustic complexity. Detailed results are presented for six children matched in pairs in terms of their average pure-tone thresholds. All children showed progress in their ability to label at least some of the contrasts. Development was usually seen for the vowel contrast before the more complex initial consonant voicing contrast. Rate of development was not closely related to average pure-tone thresholds.

The development of contrastiveness in profoundly deaf children's speech.

This paper presents some of the results from a study of certain perceptual and productive characteristics of the speech of a group of 16 severely-profoundly deaf children over a period of 4 years who formed a complete class in an oral school. The extent to which they follow a normal pattern of development is discussed.

Speech pattern element stimulation in electrical hearing.

A sensation of hearing is provided for the otherwise totally deaf adult by the use of an electrode arrangement, placed external to the cochlea, which provides only larynx frequency speech pattern information. This is normally obtained by acoustic analysis and is presented so that, although its pattern is preserved, its physical form is matched to the patient's auditory capacity. Speech-receptive improvement has been shown using interactive synthetic speech techniques, video-recorded lipreading tests, and interactive conversational-type presentations. Speech production skills are also enhanced by self-monitoring, and examples of voice range improvement and jitter reduction are given. The particular electrode system used is especially suitable for promontory stimulation in adult patients without a tympanic membrane. The work as a whole is relevant, however, to the design of other conservative prostheses for both deaf adults and children.

Voice pitch measurements in schizophrenia and depression.

A monotonous voice is produced by schizophrenic patients whose expression of emotion is damped down and by patients with a severe degree of depression. Clinically, the distinction between these two diagnostic entities is virtually impossible to establish auditorily on the basis of voice quality alone. The laryngograph has been developed recently to record laryngeal activity. It was used to study voice pitch in a series of emotionally blunted and non-blunted schizophrenics, and retarded and non-retarded depressives. The frequency distributions of the laryngographic recordings were analysed to yield kurtosis scores. The group of retarded depressives had a significantly higher kurtosis score than the group of blunted schizophrenics. Hence this technique allows an objective distinction to be made between two kinds of monotonous voice produced by psychiatric patients. Furthermore, blunted schizophrenics had a higher mean kurtosis score than non-blunted schizophrenics, indicating that this measure can also be used as an objective index of blunting of affect in schizophrenia.