No description available.

No description available.

No description available.

No description available.

Thesis (M.Sc. (Nutrition)--North-West University, Potchefstroom Campus, 2008.

Are subjects produced differently based on the transitivity of the clause they are embedded in? Based on data from a narrative reading experiment, it is shown that transitive subjects are produced with a lower f0 than intransitive subjects and that this difference is statistically significant (p∠0.05). It is suggested that the purpose for such a difference originates from a propensity for English speakers to accent new referents, which are common in the object position. By lowering the f0 of the subject, speakers increase the efficacy of an accent on a new object later in the clause. Finally, the read narrative procedure is evaluated for its strict control of stimuli, while also reproducing known intonational phenomena.

Thesis (M.Sc. (Nutrition)--North-West University, Potchefstroom Campus, 2008.

Thesis (M.Sc. (Nutrition)--North-West University, Potchefstroom Campus, 2008.

Non-linear frequency compression (NLFC) hearing aids aim to deliver high-frequency sound to a better functioning, lower frequency region of the cochlea. Despite the widespread use of frequency lowering technology, it continues to be difficult to predict candidacy. Since the aim of NLFC is to improve high-frequency audibility, possible predictors of benefit may include high-frequency hearing thresholds. NLFC alters the harmonic relationship of speech, and it has frequently been proposed that auditory training may help users adapt to the distorted acoustic signal. The aim of this thesis was twofold: firstly, to identify audiometric predictors of benefit from NLFC, and secondly to explore the role of auditory training in adaptation to NLFC. The first study aimed to determine if outcome with NLFC was related to hearing thresholds. Twenty-one experienced adult hearing aid users, with mild-to-profound high-frequency hearing loss, completed speech recognition and self-report measures with NLFC enabled and disabled over 16 weeks. The additional benefit gained on phoneme detection and word recognition tasks with NLFC enabled was positively correlated with average high-frequency hearing loss. Additional benefit began to emerge as average high-frequency hearing thresholds exceeded 70 dB HL. There was some evidence of a ‘roll-off’ in additional benefit when hearing thresholds exceeded 100 dB HL. The second study aimed to identify which training method, if any, may help adaptation to NLFC. Forty young normally hearing adults were randomly allocated to one of four groups: a training group (sentence or consonant) or a control group (passive exposure or test-only). Training led to significant improvements on novel measures of speech recognition. Generalisation was limited to near transfer i.e. sentence training led to improved sentence recognition whilst consonant training led to improved consonant recognition. Improvements following passive exposure to frequency compressed sentences were equivalent to those achieved by active sentence training. Results from this second study suggest that auditory training may improve outcome for users of NLFC hearing aids, but passive exposure may be an important confounding variable. In the final study high-frequency focused sentence and consonant training was compared to sham training (passive exposure to a talking book). Twenty-six hearing-impaired adults who were new users of NLFC were allocated to either an auditory training or a sham training group. Measures of speech recognition and self-report benefit were administered before and after four weeks of home-based training. Auditory training significantly improved speech reception thresholds. In conclusion, benefit from NLFC was dependent on hearing thresholds; as hearing thresholds increased so did benefit. Participants with severe-to-profound high-frequency hearing loss gained most benefit from NLFC. Auditory training provided alongside NLFC significantly improved speech recognition in noise but changes to all other outcome measures were not significant.

Work-related low back disorders (WRLBDs) are common and costly in the U.S. and numerous interventions aiming to reduce WRLBD risk have been developed.  In one approach, training programs incorporating the work strategies (or work methods) of experienced workers have often been proposed as a training model or a behavior target of training.  However, both the specific role of work experience in contributing to WRLBDs and the effectiveness of such an intervention approach are not well understood.  In the current research, differential work strategies of experienced workers and associated WRLBD risk were identified, in the context of several common occupational activities.  Three experiments were completed, in which both experienced workers and matched novices participated.  These experiments involved relatively short duration repetitive lifts/lowers, more prolonged lifts/lowers that induced fatigue, and dynamic pushes/pulls.  Diverse aspects of work strategies were quantified, emphasizing torso kinematics/kinetics, balance maintenance, and/or torso movement stability.  During short-term repetitive lifts/lowers, experienced workers exhibited higher torso kinematics and kinetics, suggestive of a higher risk for WRLBDs, though better balance maintenance and torso stability were evident in this group.  Thus, experienced workers may trade off an increased risk for WRLBDs to achieve better balance and torso stability.  Fatigue modified work methods during repetitive lifts/lowers in both the novice and experienced groups, though the associated contribution to WRLBDs was unclear due to opposite changes in torso kinematics vs. kinetics.  More consistently, fatigue decreased balance maintenance during lifts/lowers.  Fatigue also modified work methods adopted by experienced workers, leading to higher torso kinetics, that were suggestive of a higher risk for WRLBDs during lifts/lowers.  For dynamic pushes/pulls, experienced workers used lower torso kinematics and kinetics, suggestive of a lower risk for WRLBDs.  As a whole, these results suggest that work methods are distinct between novices and experienced workers.  Further, work experience may not consistently reduce WRLBD risk, and the influences of experience may be task specific.  Such findings can help guide the development of future interventions, particularly training, targeting the control of WRLBDs. / Ph. D.