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Objectives: This study investigated the influence of long-term talker familiarity on speech-in-speech recognition in school-age children, with a specific emphasis on the role of familiarity with the mother's voice as either the target or masker speech. Design: Open-set sentence recognition was measured adaptively in a two-talker masker. Target and masker sentences were recorded by the adult mothers of the child participants. Each child heard sentences spoken by three adult female voices during testing; their own mother's voice (familiar voice) and two unfamiliar adult female voices. Study sample: Twenty-four school age children (8-13 years) with normal hearing. Results: When the target speech was spoken by a familiar talker (the mother), speech recognition was significantly better compared to when the target was unfamiliar. When the masker was spoken by the familiar talker, there was no difference in performance relative to the unfamiliar masker condition. Across all conditions, younger children required a more favorable signal-to-noise ratio than older children. Conclusion: Implicit long-term familiarity with a talker consistently improves children's speech-in-speech recognition across the age range tested, specifically when the target talker is familiar. However, performance remains unaffected by masker talker familiarity. Additionally, while target familiarity is advantageous, it does not entirely eliminate children's increased susceptibility to competing speech.

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OBJECTIVES: This study explored the effects of different face masks on school-age children's and young adults' word recognition. DESIGN: Speech recognition thresholds were measured adaptively in a two-talker speech masker using a closed-set picture pointing task. Target words were recorded by a female talker in five conditions: no mask, transparent mask, face shield, N95 mask and surgical mask. STUDY SAMPLES: Thirty children (8-12 years) and 25 adults (18-25 years) with normal hearing. RESULTS: Both children's and adults' word recognition was most negatively impacted by the face shield. Children's recognition was also impaired by the transparent mask. No negative effects were observed for the N95 or surgical mask for either age group. CONCLUSION: School-age children, like young adults, are negatively affected by face masks when recognising speech in a two-talker speech masker, but the effects depend on the type of face mask being worn. Acoustic analyses suggest that the reflective materials used for masks impact speech signal quality and impair word recognition.

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OBJECTIVE: The purpose of this study was to 1) characterise word recognition in a speech masker for preschoolers tested using closed-set, forced-choice procedures and 2) better understand the stimulus and listener factors affecting performance. DESIGN: Speech recognition thresholds (SRTs) in a two-talker masker were evaluated using a picture-pointing response with two sets of disyllabic target words. ChEgSS words were previously developed for children ≥5 years of age, and simple words were developed for preschoolers. Familiarisation ensured accurate identification of target words before testing. STUDY SAMPLE: Participants were 3- and 4-year olds (n = 21) and young adults (n = 10) with normal hearing. RESULTS: Preschoolers and adults had significantly lower SRTs for the simple words than the ChEgSS words, and lower SRTs for early-acquired than later-acquired ChEgSS words. For both word sets, SRTs were approximately 11-dB higher for preschoolers than adults, and child age was associated with SRTs. Preschoolers' receptive vocabulary size predicted performance for ChEgSS words but not simple words. CONCLUSIONS: Preschoolers were more susceptible to speech-in-speech masking than adults, with a similar child-adult difference for the ChEgSS and simple words. Effects of receptive vocabulary in preschoolers' recognition of ChEgSS words indicate that vocabulary size is an important consideration, even when using closed-set methods.

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A multi-talker paradigm is introduced that uses different attentional processes to adjust speech-recognition scores with the goal of conducting measurements at high signal-to-noise ratios (SNR). The basic idea is to simulate a group conversation with three talkers. Talkers alternately speak sentences of the German matrix test OLSA. Each time a sentence begins with the name "Kerstin" (call sign), the participant is addressed and instructed to repeat the last words of all sentences from that talker, until another talker begins a sentence with "Kerstin". The alternation of the talkers is implemented with an adjustable overlap time that causes an overlap between the call sign "Kerstin" and the target words to be repeated. Thus, the two tasks of detecting "Kerstin" and repeating target words are to be done at the same time. The paradigm was tested with 22 young normal-hearing participants (YNH) for three overlap times (0.6 s, 0.8 s, 1.0 s). Results for these overlap times show significant differences, with median target word recognition scores of 88%, 82%, and 77%, respectively (including call-sign and dual-task effects). A comparison of the dual task with the corresponding single tasks suggests that the observed effects reflect an increased cognitive load.

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While the audible frequency range for humans spans approximately 20 Hz to 20 kHz, children display enhanced sensitivity relative to adults when detecting extended high frequencies (frequencies above 8 kHz; EHFs), as indicated by better pure tone thresholds. The impact that this increased hearing sensitivity to EHFs may have on children's speech recognition has not been established. One context in which EHF hearing may be particularly important for children is when recognizing speech in the presence of competing talkers. In the present study, we examined the extent to which school-age children (ages 5-17 years) with normal hearing were able to benefit from EHF cues when recognizing sentences in a two-talker speech masker. Two filtering conditions were tested: all stimuli were either full band or were low-pass filtered at 8 kHz to remove EHFs. Given that EHF energy emission in speech is highly dependent on head orientation of the talker (i.e., radiation becomes more directional with increasing frequency), two masker head angle conditions were tested: both co-located maskers were facing 45°, or both were facing 60° relative to the listener. The results demonstrated that regardless of age, children performed better when EHFs were present. In addition, a small change in masker head orientation also impacted performance, with better recognition at 60° compared to 45°. These findings suggest that EHF energy in the speech signal above 8 kHz is beneficial for children in complex listening situations. The magnitude of benefit from EHF cues and talker head orientation cues did not differ between children and adults. Therefore, while EHFs were beneficial for children as young as 5 years of age, children's generally better EHF hearing relative to adults did not provide any additional benefit.

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Daily speech communication often takes place in suboptimal listening conditions, in which interlocutors typically need to segregate the target signal from the background sounds. The present study investigated the influence on speech recognition of a relatively familiar foreign accent in background speech (Exp. 1) and whether short-term immediate exposure to the target talker's voice (Exp. 2) or the background babble (Exp. 3) would either help or hinder the segregation of target from background. A total of 72 native Dutch participants were asked to listen to Dutch target sentences in the presence of Dutch or German-accented Dutch babble without (Exp. 1) or with (Exps. 2 and 3) an exposure phase. Their task was to write down what they heard. The results of Experiment 1 revealed that listeners gained a release from masking when the background speech was accented, indicating that dissimilar and less familiar signals are easier to segregate effectively. Experiment 2 demonstrated that short-term immediate exposure to the target talker had no effect on speech-in-speech recognition, whereas exposure to the background babble could hinder separating the target voice from the background speech (Exp. 3). However, this reduced release from masking only appeared in the more difficult and more familiar babble condition (Dutch in Dutch), in which the speech recognition system may have remained attuned to the babble as a potential source of communicatively relevant information. Overall, this research provides evidence that both short-term adaptation and the degrees of target-background similarity and familiarity are of importance for speech-in-speech recognition.

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