Effects of Signal and Masker Uncertainty on Children’s Detection

1995 ◽  
Vol 38 (2) ◽  
pp. 503-511 ◽  
Author(s):  
Prudence Allen ◽  
Frederic Wightman
Keyword(s):  
Psychometric Function ◽  
Forced Choice ◽  
Preschool Age ◽  
Signal Frequency ◽  
Focused Attention ◽  
Random Frequency ◽  
Random Level

This paper reports the results of two experiments that examined the effects of signal and masker uncertainty on preschool-age children’s and adults’ detection of tonal signals in noise maskers. In Experiment 1 (signal uncertainty) the signal was randomly at 501 or 2818 Hz. The majority of the adult listeners showed a slight decrement in performance consistent with an ability to monitor both frequencies simultaneously. The majority of the children, however, showed no decrement in performance, suggesting that the children may not have focused attention at the signal frequency even when it was fixed. In Experiment 2 (masker uncertainty), random-frequency, random-level, tonal distracters were added to each interval of the 2 alternative-forced-choice (2afc) procedure. The effect of masker uncertainty was much larger than that of signal uncertainty. For most of the adult listeners and some of the children, the distracters produced higher thresholds (on average by 10 dB) and shallower psychometric function slopes. For most of the children, thresholds increased by 20 dB or more and psychometric functions were often nearly flat. This paper reports the results of two experiments that examined the effects of signal and masker uncertainty on preschool-age children's and adults' detection of tonal signals in noise maskers. In Experiment 1 (signal uncertainty) the signal was randomly at 501 or 2818 Hz. The majority of the adult listeners showed a slight decrement in performance consistent with an ability to monitor both frequencies simultaneously. The majority of the children, however, showed no decrement in performance, suggesting that the children may not have focused attention at the signal frequency even when it was fixed. In Experiment 2 (masker uncertainty), random-frequency, random-level, tonal distracters were added to each interval of the 2 alternative-forced-choice (2afc) procedure. The effect of masker uncertainty was much larger than that of signal uncertainty. For most of the adult listeners and some of the children, the distracters produced higher thresholds (on average by 10 dB) and shallower psychometric function slopes. For most of the children, thresholds increased by 20 dB or more and psychometric functions were often nearly flat.

scholarly journals Attention and Signal Detection

Information ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 254 ◽  
Author(s):  
Reeves
Keyword(s):  
Visual Field ◽  
Signal Detection ◽  
Signal Detection Theory ◽  
Detection Theory ◽  
Forced Choice ◽  
Focused Attention

In this paper, I first review signal detection theory (SDT) approaches to perception, and then discuss why it is thought that SDT theory implies that increasing attention improves performance. Our experiments have shown, however, that this is not necessarily true. Subjects had either focused attention on two of four possible locations in the visual field, or diffused attention to all four locations. The stimuli (offset letters), locations, conditions, and tasks were all known in advance, responses were forced-choice, subjects were properly instructed and motivated, and instructions were always valid—conditions which should optimize signal detection. Relative to diffusing attention, focusing attention indeed benefitted discrimination of forward from backward pointing Es. However, focusing made it harder to identify a randomly chosen one of 20 letters. That focusing can either aid or disrupt performance, even when cues are valid and conditions are idealized, is surprising, but it can also be explained by SDT, as shown here. These results warn the experimental researcher not to confuse focusing attention with enhancing performance, and warn the modeler not to assume that SDT is unequivocal.

Frequency Resolution in Children

1989 ◽  
Vol 32 (2) ◽  
pp. 317-322 ◽  
Author(s):  
Prudence Allen ◽  
Frederic Wightman ◽  
Doris Kistler ◽  
Terrence Dolan
Keyword(s):  
Video Game ◽  
Wide Band ◽  
Noise Spectrum ◽  
Forced Choice ◽  
Frequency Resolution ◽  
Signal Frequency ◽  
School Aged Children ◽  
The Mean ◽  
The Difference ◽  
Signal Threshold

The auditory frequency resolving ability of preschool children, school-aged children, and adults was assessed in a standard forced-choice masking experiment. Thresholds for pure-tone signals at 500 Hz, 2000 Hz, and 4000 Hz were obtained in two masking conditions. In one condition, the masker was a 4000-Hz-wide band of noise centered at the signal frequency; in the other, there was a notch in the noise spectrum, approximately one-half octave wide and 50 dB deep, centered at the signal frequency. Frequency resolving ability was inferred from the difference in signal threshold between the two masking conditions. The adaptive forced-choice psychophysical procedure was embedded in a video game in order to obtain rigorous pyschophysical data within the attentional limits of young children. This procedure produced data from children as young as 3 years old that were qualitatively indistinguishable from adult data. However, the threshold estimates from the children were more variable from run to run than were the estimates obtained from adults. The mean data from this experiment suggest that frequency resolving ability improves at all frequencies with increasing age.

Psychometric Functions for Children’s Detection of Tones in Noise

1994 ◽  
Vol 37 (1) ◽  
pp. 205-215 ◽  
Author(s):  
Prudence Allen ◽  
Frederic Wightman
Keyword(s):  
Psychometric Function ◽  
Forced Choice ◽  
Choice Task ◽  
Large Variability ◽  
Forced Choice Task ◽  
The Individual ◽  
Over Time

This article reports the results of an experiment that used a two-alternative forced-choice task to measure the ability of 3- to 5-year-old children to detect 501 Hz, 1000 Hz, and 2818 Hz sinusoids in noise. Psychometric functions were fit to each individual’s data, and thresholds (signal level required for 75% correct) were interpolated from the fitted functions. Results showed that, on average, the children’s thresholds were higher and the slopes of their psychometric functions were shallower than those of the adults. However, the between-subjects variability in the children’s data was large, and the performance of many individual children was not well described by group mean performance. One-third of the children produced thresholds that were elevated by an average of 10 dB but psychometric function slopes that were adult-like. Another one-third of the children produced thresholds that were elevated relative to those of the adults by an average of 20 dB and psychometric function slopes that were very shallow. The data from a smaller group of children showed large variability in psychometric function slope and threshold, and for a very few children performance was at chance regardless of the signal level. A replication of the study several months later showed that for most listeners the individual patterns of performance persisted over time.

scholarly journals Sampling Plans for Fitting the Psychometric Function

2005 ◽  
Vol 8 (2) ◽  
pp. 256-289 ◽  
Author(s):  
Miguel A. García-Pérez ◽  
Rocío Alcalá-Quintana
Keyword(s):  
Parameter Estimation ◽  
Psychometric Function ◽  
Estimation Method ◽  
Forced Choice ◽  
Estimation Methods ◽  
Parameter Estimates ◽  
Mathematical Form ◽  
Sampling Plans ◽  
Forced Choice Tasks ◽  
Choice Tasks

Research on estimation of a psychometric function Ψ has usually focused on comparing alternative algorithms to apply to the data, rarely addressing how best to gather the data themselves (i.e., what sampling plan best deploys the affordable number of trials). Simulation methods were used here to assess the performance of several sampling plans in yes–no and forced-choice tasks, including the QUEST method and several variants of up–down staircases and of the method of constant stimuli (MOCS). We also assessed the efficacy of four parameter estimation methods. Performance comparisons were based on analyses of usability (i.e., the percentage of times that a plan yields usable data for the estimation of all the parameters of Ψ) and of the resultant distributions of parameter estimates. Maximum likelihood turned out to be the best parameter estimation method. As for sampling plans, QUEST never exceeded 80% usability even when 1000 trials were administered and rendered accurate estimates of threshold but misestimated the remaining parameters. MOCS and up–down staircases yielded similar and acceptable usability (above 95% with 400–500 trials) and, although neither type of plan allowed estimating all parameters with optimal precision, each type appeared well suited to estimating a distinct subset of parameters. An analysis of the causes of this differential suitability allowed designing alternative sampling plans (all based on up–down staircases) for yes–no and forced-choice tasks. These alternative plans rendered near optimal distributions of estimates for all parameters. The results just described apply when the fitted Ψ has the same mathematical form as the actual Ψ generating the data; in case of form mismatch, all parameters except threshold were generally misestimated but the relative performance of all the sampling plans remained identical. Detailed practical recommendations are given.

Biracial Testing: The Question of Clinicians' Influence on Children’s Test Performance

1977 ◽  
Vol 8 (1) ◽  
pp. 5-14 ◽  
Author(s):  
David L. Ratusnik ◽  
Roy A. Koenigsknecht
Keyword(s):  
Clinical Setting ◽  
Test Performance ◽  
Test Scores ◽  
Preschool Age ◽  
Speech And Language ◽  
Black And White ◽  
Drawing Test ◽  
Lower Socioeconomic ◽  
Preschool Age Children

Six speech and language clinicians, three black and three white, administered the Goodenough Drawing Test (1926) to 144 preschoolers. The four groups, lower socioeconomic black and white and middle socioeconomic black and white, were divided equally by sex. The biracial clinical setting was shown to influence test scores in black preschool-age children.

Quantifying the Effects of Background Speech Babble on Preschool Children's Novel Word Learning in a Multisession Paradigm: A Preliminary Study

2020 ◽  
Vol 63 (1) ◽  
pp. 345-356
Author(s):  
Meital Avivi-Reich ◽  
Megan Y. Roberts ◽  
Tina M. Grieco-Calub
Keyword(s):  
Word Learning ◽  
Signal To Noise Ratio ◽  
Preschool Age ◽  
Exposure Condition ◽  
Signal To Noise ◽  
Verbal Recall ◽  
Referent Selection ◽  
Main Effect ◽  
Noise Ratio ◽  
Novel Word Learning

Purpose This study tested the effects of background speech babble on novel word learning in preschool children with a multisession paradigm. Method Eight 3-year-old children were exposed to a total of 8 novel word–object pairs across 2 story books presented digitally. Each story contained 4 novel consonant–vowel–consonant nonwords. Children were exposed to both stories, one in quiet and one in the presence of 4-talker babble presented at 0-dB signal-to-noise ratio. After each story, children's learning was tested with a referent selection task and a verbal recall (naming) task. Children were exposed to and tested on the novel word–object pairs on 5 separate days within a 2-week span. Results A significant main effect of session was found for both referent selection and verbal recall. There was also a significant main effect of exposure condition on referent selection performance, with more referents correctly selected for word–object pairs that were presented in quiet compared to pairs presented in speech babble. Finally, children's verbal recall of novel words was statistically better than baseline performance (i.e., 0%) on Sessions 3–5 for words exposed in quiet, but only on Session 5 for words exposed in speech babble. Conclusions These findings suggest that background speech babble at 0-dB signal-to-noise ratio disrupts novel word learning in preschool-age children. As a result, children may need more time and more exposures of a novel word before they can recognize or verbally recall it.

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