Background Many audiologists have observed a situation where a patient appears to understand something spoken by his/her spouse or a close friend but not the same information spoken by a stranger. However, it is not clear whether this observation reflects choice of communication strategy or a true benefit derived from the talker’s voice. Purpose The current study measured the benefits of long-term talker familiarity for older individuals with hearing impairment in a variety of listening situations. Research Design In Experiment 1, we measured speech recognition with familiar and unfamiliar voices when the difficulty level was manipulated by varying levels of a speech-shaped background noise. In Experiment 2, we measured the benefit of a familiar voice when the background noise was other speech (informational masking). Study Sample A group of 31 older listeners with high-frequency sensorineural hearing loss participated in the study. Fifteen of the participants served as talkers, and sixteen as listeners. In each case, the talker-listener pair for the familiar condition represented a close, long-term relationship (spouse or close friend). Data Collection and Analysis Speech-recognition scores were compared using controlled stimuli (low-context sentences) recorded by the study talkers. The sentences were presented in quiet and in two levels of speech-spectrum noise (Experiment 1) as well as in multitalker babble (Experiment 2). Repeated-measures analysis of variance was used to compare performance between the familiar and unfamiliar talkers, within and across conditions. Results Listeners performed better when speech was produced by a talker familiar to them, whether that talker was in a quiet or noisy environment. The advantage of the familiar talker was greater in a more adverse listening situation (i.e., in the highest level of background noise), but was similar for speech-spectrum noise and multi-talker babble. Conclusions The present data support a frequent clinical observation: listeners can understand their spouse better than a stranger. This effect was present for all our participants and occurred under strictly controlled conditions in which the only possible cue was the voice itself, rather than under normal communicative conditions where listener accommodation strategies on the part of the talker may confound the measurable benefit. The magnitude of the effect was larger than shown for short-term familiarity in previous work. This suggests that older listeners with hearing loss who inherently operate under deficient auditory conditions can benefit from experience with the voice characteristics of a long-term communication partner over many years of a relationship.

ABSTRACT. In this paper we argue against the findings presented in Hay & Bauer 2007, which show a positive correlation between population size and phoneme inventory size. We argue that the positive correlation is an artifact of the authors' statistical technique and biased data set.Using a hierarchical mixed model to account for genealogical relatedness of languages, and a much larger and more diverse sample of the world's languages, we find little support for population size as an explanatory predictor of phoneme inventory size once the genealogical relatedness of languages is accounted for.

Successful speech communication often requires selective attention to a target stream amidst competing sounds, as well as the ability to switch attention among multiple interlocutors. However, auditory attention switching negatively affects both target detection accuracy and reaction time, suggesting that attention switches carry a cognitive cost. Pupillometry is one method of assessing mental effort or cognitive load. Two experiments were conducted to determine whether the effort associated with attention switches is detectable in the pupillary response. In both experiments, pupil dilation, target detection sensitivity, and reaction time were measured; the task required listeners to either maintain or switch attention between two concurrent speech streams. Secondary manipulations explored whether switch-related effort would increase when auditory streaming was harder. In experiment 1, spatially distinct stimuli were degraded by simulating reverberation (compromising across-time streaming cues), and target-masker talker gender match was also varied. In experiment 2, diotic streams separable by talker voice quality and pitch were degraded by noise vocoding, and the time alloted for mid-trial attention switching was varied. All trial manipulations had some effect on target detection sensitivity and/or reaction time; however, only the attention-switching manipulation affected the pupillary response: greater dilation was observed in trials requiring switching attention between talkers.

Analysis of pupil dilation has been used as an index of attentional effort in the auditory domain. Previous work has modeled the pupillary response to attentional effort as a linear time-invariant system with a characteristic impulse response, and used deconvolution to estimate the attentional effort that gives rise to changes in pupil size. Here it is argued that one parameter of the impulse response (the latency of response maximum, t(max)) has been mis-estimated in the literature; a different estimate is presented, and it is shown how deconvolution with this value of t(max) yields more intuitively plausible and informative results.

Dyslexia is associated with abnormal performance on many auditory psychophysics tasks, particularly those involving the categorization of speech sounds. However, it is debated whether those apparent auditory deficits arise from (a) reduced sensitivity to particular acoustic cues, (b) the difficulty of experimental tasks, or (c) unmodeled lapses of attention. Here we investigate the relationship between phoneme categorization and reading ability, with special attention to the nature of the cue encoding the phoneme contrast (static versus dynamic), differences in task paradigm difficulty, and methodological details of psychometric model fitting. We find a robust relationship between reading ability and categorization performance, show that task difficulty cannot fully explain that relationship, and provide evidence that the deficit is not restricted to dynamic cue contrasts, contrary to prior reports. Finally, we demonstrate that improved modeling of behavioral responses suggests that performance does differ between children with dyslexia and typical readers, but that the difference may be smaller than previously reported.