Factors responsible for remote-frequency masking in children and adults

Susceptibility to remote-frequency masking in children and adults was evaluated with respect to three stimulus features: (1) masker bandwidth, (2) spectral separation of the signal and masker, and (3) gated versus continuous masker presentation. Listeners were 4- to 6-year-olds, 7- to 10-year-olds, and adults. Detection thresholds for a 500-ms, 2000-Hz signal were estimated in quiet or presented with a band of noise in one of four frequency regions: 425–500 Hz, 4000–4075 Hz, 8000–8075 Hz, or 4000–10 000 Hz. In experiment 1, maskers were gated on in each 500-ms interval of a three-interval, forced-choice adaptive procedure. Masking was observed for all ages in all maskers, but the greatest masking was observed for the 4000–4075 Hz masker. These findings suggest that signal/masker spectral proximity plays an important role in remote-frequency masking, even when peripheral excitation associated with the signal and masker does not overlap. Younger children tended to have more masking than older children or adults, consistent with a reduced ability to segregate simultaneous sounds and/or listen in a frequency-selective manner. In experiment 2, detection thresholds were estimated in the same noises, but maskers were presented continuously. Masking was reduced for all ages relative to gated conditions, suggesting improved segregation and/or frequency-selective listening

Behavioral Assessment of Hearing in 2 to 4 Year-old Children: A Two-interval, Observer-based Procedure Using Conditioned Play-based Responses

Collecting reliable behavioral data from toddlers and preschoolers is challenging. As a result, there are significant gaps in our understanding of human auditory development for these age groups. This paper describes an observer-based procedure for measuring hearing sensitivity with a two-interval, two-alternative forced-choice paradigm. Young children are trained to perform a play-based, motor response (e.g., putting a block in a bucket) whenever they hear a target signal. An experimenter observes the child's behavior and makes a judgment about whether the signal was presented during the first or second observation interval; the experimenter is blinded to the true signal interval, so this judgment is based solely on the child's behavior. These procedures were used to test 2 to 4 year-olds (n = 33) with no known hearing problems. The signal was a 1,000 Hz warble tone presented in quiet, and the signal level was adjusted to estimate a threshold corresponding to 71%-correct detection. A valid threshold was obtained for 82% of children. These results indicate that the two-interval procedure is both feasible and reliable for use with toddlers and preschoolers. The two-interval, observer-based procedure described in this paper is a powerful tool for evaluating hearing in young children because it guards against response bias on the part of the experimenter

Spatial Release From Masking in Children: Effects of Simulated Unilateral Hearing Loss

The purpose of this study was twofold: 1) to determine the effect of an acute simulated unilateral hearing loss on children’s spatial release from masking in two-talker speech and speech-shaped noise, and 2) to develop a procedure to be used in future studies that will assess spatial release from masking in children who have permanent unilateral hearing loss. There were three main predictions. First, spatial release from masking was expected to be larger in two-talker speech than speech-shaped noise. Second, simulated unilateral hearing loss was expected to worsen performance in all listening conditions, but particularly in the spatially separated two-talker speech masker. Third, spatial release from masking was expected to be smaller for children than for adults in the two-talker masker

Effect of response context and masker type on word recognition in school-age children and adults

In adults, masked speech recognition improves with the provision of a closed set of response alternatives. The present study evaluated whether school-age children (5–13 years) benefit to the same extent as adults from a forced-choice context, and whether this effect depends on masker type. Experiment 1 compared masked speech reception thresholds for disyllabic words in either an open-set or a four-alternative forced-choice (4AFC) task. Maskers were speech-shaped noise or two-talker speech. Experiment 2 compared masked speech reception thresholds for monosyllabic words in two 4AFC tasks, one in which the target and foils were phonetically similar and one in which they were dissimilar. Maskers were speech-shaped noise, amplitude-modulated noise, or two-talker speech. For both experiments, it was predicted that children would not benefit from the information provided by the 4AFC context to the same degree as adults, particularly when the masker was complex (two-talker) or when audible speech cues were temporally sparse (modulated-noise). Results indicate that young children do benefit from a 4AFC context to the same extent as adults in speech-shaped noise and amplitude-modulated noise, but the benefit of context increases with listener age for the two-talker speech masker

Children's Identification of Consonants in a Speech-Shaped Noise or a Two-Talker Masker

This study evaluated child-adult differences for consonant identification in a noise or a two-talker masker. Error patterns were compared across age and masker type to test the hypothesis that errors with the noise masker reflect limitations in the peripheral encoding of speech, whereas errors with the two-talker masker reflect target-masker confusions within the central auditory system

Masking by a Remote-Frequency Noise Band in Children and Adults

OBJECTIVE: Werner and Bargones (1991) observed that a 4-10-kHz noise band can mask a 1-kHz signal during infancy. The purpose of this study was to examine whether remote-noise masking extends into the school-aged years. DESIGN: Listeners were 4-6-yr-olds, 7-9-yr-olds, and adults. Detection thresholds were measured for the 1-kHz signal in quiet and in the presence of the remote-frequency noise. In separate conditions, masker level was either 40 or 60 dB SPL. RESULTS: On average, thresholds for the 1-kHz signal were elevated in the presence of the remote-frequency noise for 4-6-yr-olds, but not for 7-9-yr-olds or adults. Group average thresholds were similar across masker levels, indicating nonperipheral effects. CONCLUSIONS: Susceptibility to remote-frequency masking in children extends to 4-6 yrs of age for some children

Adults, but not children, benefit from a pretrial signal cue in a random-frequency, two-tone masker

This study examined the benefit of a pretrial cue, a preview of the signal, on children's (5–10 years) and adults' detection of a 1000-Hz pure-tone signal in a broadband noise or a random-frequency, two-tone masker. No cuing effect was observed with the noise masker, regardless of listener age. In contrast, all but one adult benefited from the cue with the two-tone masker (average = 9.4 dB). Most children showed no cuing effect (average = 0.1 dB) with the two-tone masker. These results suggest that, unlike adults, the provision of a pretrial cue does not promote frequency-selective listening during detection for 5- to 10-year-olds

Development of Open-Set Word Recognition in Children: Speech-Shaped Noise and Two-Talker Speech Maskers

The goal of this study was to establish the developmental trajectories for children’s open-set recognition of monosyllabic words in each of two maskers: two-talker speech and speech-shaped noise

Linguistic Masking Release in School-Age Children and Adults

This study assessed if 6- to 8-year-old children benefit from a language mismatch between target and masker speech for sentence recognition in a 2-talker masker

Linguistic Masking Release in School-Age Children and Adults

This study assessed if 6- to 8-year-old children benefit from a language mismatch between target and masker speech for sentence recognition in a 2-talker masker