VOICE PARAMETER EXTRACTOR USING ORAL AIR FLOW PHASE I-SYSTEM FOR QUANTITATIVE ASSESSMENT OF SPEECH

THE VOLUME VELOCITY WAVEFORM OF THE AIR FLOW THROUGH THE LARYNX DURING VOICED SPEECH IS A GOOD INDICATOR OF THE VIBRATORY PATTERN OF THE VOCAL CORDS (OR VOCAL FOLDS), ESPECIALLY IF THE AVERAGE LUNG PRESSURE IS ALSO KNOWN. THOUGH THIS AIR FLOW IS DIFFICULT TO MEASURE DIRECTLY, IT CAN BE INFERRED FROM THE PATTERN OF AIR FLOW OR PRESSURE IN OR NEAR THE MOUTH, BY A PROCESS KNOWN AS "INVERSE FILTERING". HOWEVER, AN INVERSE FILTER REQUIRES A KNOWLEDGEOF THE TRANSMISSION CHARACTERISTICS OF THE VOCAL TRACT BETWEEN THE LARYNX AND THE MOUTH (OR FROM THE LARYNX TO THE PRESSURE/FLOW SENSOR USED) AND THEREFORE IS DIFFICULT TO APPLY IN MANY CLINICAL SITUATIONS. THIS PROPOSAL DESCRIBES A RELATIVELY SIMPLE AND ROBUST METHOD FOR PROCESSING A WAVEFORM OF THE AIR FLOW AT THE MOUTH SO AS TO PRODUCE A CLINICALLY-USEFUL REPRESENTATION OF THE LARYNGEAL FLOW THAT DOES NOT REQUIRES A HIGH LEVEL OF TRAINING TO IMPLEMENT. ITIS PROPOSED THAT THE METHOD BE IMPLEMENTED ON A MICROCOMPUTER AND COMPARED WITH ACCURATE INVERSE FILTERING FOR A VARIETY OF NORMAL AND ABNORMAL VOICE QUALTIES. ASSESSMENT OF THE SPEECH OF COMMUNICATIVELY HANDICAPPED INDIVIDUALS IS ONE OF THE PRIMARY ACTIVITIES PERFORMED BY SPEECH-LANGUAGE PATHOLOGISTS. THIS PROJECT EXAMINES THE FEASIBILITY OF A SEMI-AUTOMATED, COMPREHENSIVE SYSTEM FOR THE QUANTITATIVE ASSESSMENT OF SPEECH TO BE IMPLEMENTED WITHCURRENTLY AVAILABLE TECHNOLOGY. THE ENVISIONED SYSTEM IS DESIGNED TO ACQUIRE RAW SPEECH INPUT DATA, AS WELL AS A TRAINED CLINICIAN'S OBSERVATIONS, IN THE COURSE OF THE TESTING SESSION. THE SYSTEM FOLLOWS A TESTING BATTERY MODEL, EXAMINING SUCH FACTORS AS: (1) CLIENT'S BACKGROUND/HISTORY; (2) SINGLE-WORD ARTICULATION ABILITY; (3) SENTENCE ARTICULATION ABILITY; (4) RECEPTIVE ARTICULATION ABILITIES; (5) SPEECH MOTOR FUNCTIONS; AND (6) PERIPHERAL INTEGRITY OF THE SPEECH MECHANISM. AS A FIRST STEP TOWARD THE ENVISIONED SYSTEM, THIS STUDY IS COMPRISED OF A SINGLE-WORD ARTICULATION TEST FOLLOWED BY MISARTICULATION ANALYSES IN ORDER TO EXAMINE THE EXTENT TO WHICH EXISTING SPEECH RECOGNITION TECHNOLOGY CAN BE ADAPTED TO PROVIDE ANALYSES AT THE PHONETIC LEVEL THAT IS CONSISTENTWITH THE CLINICIAN'S ASSESSMENT OF THE CLIENT'S ARTICULATIONSKILLS. IF FEASIBILITY IS VALIDATED, PHASE II WILL BE DEVOTED TO IMPLEMENTING THE ANALYSIS ALGORITHM AND ASSOCIATED DATA MANAGEMENT SOFTWARE FUNCTIONS REQUIRED TO AUTOMATE THE ASSESSMENT PROCESS, AND FURTHER LEVELS OF ANALYSIS WILL BE DEVELOPED INCLUDING PHONOLOGICAL PROCESS ANALYSIS, PHONETIC CONTEXT ANALYSES OF ERROR SOUNDS, AND ACOUSTIC ANALYSES OF ERROR SOUNDS.