A commonly made, but rarely defended, assumption is that phonetic reduction processes apply to hyperarticulated phonetic targets. Results from experiments reported in this paper support this assumption. In various experimental conditions, listeners adjusted the input parameters of a speech synthesizer until the vowels it produced sounded like the vowels found in a set of example words. A preliminary study indicated that the method of adjustment is a feasible tool for studying vowel systems. Interestingly, listeners in the study chose vowels that were systematically different from those measured in productions of the set of example words: high vowels were higher, low vowels were lower, front vowels were farther front, and back vowels were farther back. We hypothesized that this extreme vowel space corresponds to phonetic targets that are hyperarticulated: HYPERSPACE. This hypothesis was tested in the two main experiments. The first experiment controlled for possible effects of instructions and phonetic training on the listeners' choices. In the second experiment, we improved the naturalness and distinctiveness of the synthetic vowels. The results indicate that the extreme vowels chosen by the listeners were consistent with those produced in hyperarticulated speech; moreover, the hyperspace effect is robust across experimental conditions. These results validate the hypothesis that phonetic targets are hyperarticulated, and are consistent with a two-stage model of phonetic implementation: at the first stage distinctive features are mapped to hyperarticulated phonetic targets, and at the second stage these phonetic targets are reduced.

Objective To determine if naturally produced speech stimuli evoke distinct neural response patterns that can be reliably recorded in individuals. Design Auditory cortical evoked potentials were obtained from seven normal-hearing young adults in response to four naturally produced speech tokens (/bi/, /pi/, /ʃi/, and /si/). Stimuli were tokens from the standardized UCLA version of the Nonsense Syllable Test (NST) (Dubno & Schaefer, 1992). Using a repeated measures design, subjects were tested and then retested within an 8-day period. Results Auditory cortical evoked potentials elicited by naturally produced speech sounds were reliably recorded in individuals. Also, naturally produced speech tokens, representing different acoustic cues, evoked distinct neural response patterns. Conclusions 1) Cortical evoked potentials elicited by naturally produced speech sounds can be reliably recorded in individuals. 2) Naturally produced speech tokens, representing different acoustic cues, evoke distinct neural response patterns. 3) Given the reliability of the response, this work has potential application to the study of neural processing of speech in individuals with communication disorders as well as changes over time after various types of auditory rehabilitation.

Background:Many audiologists have observed a situation where a patient appears to understand something spoken by his or 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 16 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 multitalker 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.

In this discussion note 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.