Herbert L. Pick

Inhibiting the Lombard effect

The Lombard effect is the tendency to increase ones vocal intensity in noise. The present study reports three experiments that test the robustness of the Lombard effect when speakers are given instructions and training with visual feedback to help suppress it. The Lombard effect was found to be extremely stable and robust. Instructions alone had little influence on the response to the noise among untrained speakers. When visual feedback correlated with vocal intensity was presented, however, subjects could inhibit the Lombard response. Furthermore, the inhibition remained after the visual feedback was removed. The data are interpreted as indicating that the Lombard response is largely automatic and not ordinarily under volitional control. When subjects do learn to suppress the effect, they seem to do so by changing overall vocal level rather than their specific response to the noise.

Auditory feedback in the regulation of voice

Adult speakers participated in a spontaneous speech task in which the intensity of their auditory feedback through earphones was systematically manipulated over a 20‐dB‐SPL range. In Experiment I, Ss showed a statistically significant but slight tendency to decrease their vocal intensity as sidetone was amplified. The effect was greatest when subjects were instructed to attend to their sidetone and to compensate for any changes in loudness. In Experiment II, the same procedures were repeated except that 80‐dB‐SPL noise was added in the earphones. Addition of the noise resulted in considerably enhanced sidetone‐amplification effects, even when Ss were instructed to keep their vocal level constant. In Experiment III, several levels of noise (0, 60, 70, 80 dB SPL) were used and it was noted that the greater the noise, the more substantial were the sidetone‐amplification effects. In Experiment IV, subjects were instructed to talk either louder or softer than usual, with and without noise. The data from this l...

A developmental and analytic study of the size-weight illusion☆

Abstract The size-weight illusion was measured under three conditions in S s ranging in age from 4 to 16 years, and adults. Presentation conditions included one in which size of the objects was registered both visually and haptically, a second in which S s were blindfolded and size was registered only haptically, and a third in which S s held the objects by strings and size was registered only visually. In the visual condition, the magnitude of the illusion was low and decreased with age; in the haptic condition the magnitude increased with age; in the visual-haptic condition it remained stable. It was suggested that developmental trends in magnitude of the illusion under the three conditions reflected differences in intermodal and intramodal integration.

Perceptual Integration in Children

Publisher Summary This chapter focuses on the diverse experimental designs or tasks used in the investigation of childrens perceptual integration. The purpose of this synthesis is to find trends and identify persistent problems. The discussion focuses on methodological problems in the study of intermodal integration, to indicate where there are gaps in current knowledge, and to suggest substantive generalizations or hypotheses. From a methodological point of view, the potential usefulness of intra-intermodal experimental designs and sighted-blind comparisons is suggested. Currently available data using the intra-intermodal design are not always consistent from one investigator to another but this is probably because of procedural differences rather than a weakness of the design. Designs in which perceptual behavior, scanning, attending, and so on are studied directly are advocated, as are designs that include qualitative analysis of discrimination errors. It is noted that in localization studies the nature of the response should be taken into consideration along with the nature of the stimulus. Viewing localization as an intermodal task emphasizes the importance of the response modality.

Young children's use of models and photographs as spatial representations☆

Abstract The ability of 2.5- and 3-year-old children to use a scale model and photographs as representations of a space is examined here, as a replication and extension of DeLoache (1987, 1989a, 1989b, 1990, 1991) . Like DeLoache, the results of the present study indicate that 2.5-year-olds have great difficulty when asked to use information from a scale model of one place; they do not have this trouble with photographs of the region. However, they have similar difficulties with using photographs when the space depicted by the photograph is characterized as belonging to another agent. This combination of results suggest that both the three-dimensionality and “ownership” may interfere with appreciating the “dual orientation” of some representations as both real things in themselves and representations of something else, as suggested by DeLoache.

Visual motion influences locomotion in a treadmill virtual environment

This paper describes the use of a treadmill-based virtual environment (VE) to investigate the influence of visual motion on locomotion. First, we demonstrate that a computer-controlled treadmill coupled with a wide field of view computer graphics display can be used to study interactions between perception and action. Previous work has demonstrated that humans calibrate their visually-directed actions to changing circumstances in their environment. Using a treadmill VE, we show that calibration of action is reflected in the real world as a result of manipulating the relation between the speed of visual flow, presented using computer graphics, and the speed of walking on a treadmill. Second, we extend the methodology in our treadmill VE to investigate an open question involving human gait transitions and show that the speed of visual motion influences the speed at which the gait transition occurs. These results demonstrate both the effectiveness of treadmill-based VEs in simulating the perceptual-motor effects of walking through the real world and the value of such systems in addressing basic perceptual questions that would otherwise be difficult to explore.

Cross-modal transfer and improvement of form discrimination☆

Abstract Two hypotheses about learning during improvement of discrimination were investigated in cross-modal transfer of training experiments. First-grade children were trained to discriminate among a set of letter-like forms and their performance in a similar second learning task in a different modality was evaluated. Half the S s learned visual discriminations first and tactual discriminations second; half learned tactual discriminations first and visual discriminations second. Results supported the hypothesis that learning dimensions of difference is basic to improvement in such discriminations and suggested that this learning can be transferred from one modality to another. The conditions under which prototype learning accompanies learning dimensions of difference and is transferred from one modality to another cannot be defined unequivocally.

Visual and tactual identification of form orientation

Abstract Normally sighted Ss, 4 years old to adults, made form orientation judgments tactually or visually. Partially sighted and totally blind Ss, 6 years old to adults, made form orientation judgments tactually. Normally sighted Ss showed strong visual orientation identification which were consistent across the age range. Neither normally sighted nor totally blind Ss showed any clear tactual orientation identifications. Partially sighted Ss showed tactual orientation identifications similar to the visual identifications made by normally sighted Ss. The meaning of these results for the perception of form orientation is discussed.

Reliability of sidetone amplification effect in vocal intensity.

When the auditory feedback of a speakers own voice is amplified the speaker reasonably tends to lower his voice. The reliability of this so called sidetone amplification effect was investigated in two experiments. In the first experiment feedback was modulated gradually during a session. In the second experiment the sidetone amplification effect was assessed over five successive days of testing. In both experiments the sidetone effect was very stable despite rather different eliciting conditions.

Auditory feedback and speech development.

Publisher Summary This chapter evaluates the role of feedback, particularly auditory feedback, in the development of speech in children. In the recent enthusiasm for exploring rule-governed bases of linguistic competence, the fact that speech is a highly coordinated motor skill has been almost ignored. Competence theories have ruled the imagination of researchers whereas performance data have been grudgingly accepted as the imperfect source from which competence theories are derived. As important as linguistic considerations are, they inevitably take form through an expressive system such as speech, writing, or signing, and such a system could scarcely function without the contribution of feedback, at least during certain stages of development. Under normal circumstances, speech clearly is multiply determined. Speakers acquire the language to which they have been exposed in the presence of different kinds of listeners and in a variety of social and physical situations. Although it is a motor skill, speech is the expression of linguistic codes and communication needs. Speakers talk louder in noise and also to impress a listener with their determination. Choice of words, speech rate, and inflectional pattern are all multiply determined, reflecting the contributions of social and physical variables, as well as the physiological constraints of the speech system. The relationship between forms of feedback and the various parameters of speech production are well worth exploring in future research. The area is an exciting one, as it pertains both to normal and deviant speech development.