Female Talkers Research Articles

Difference in Speech Recognition between a Default and Programmed Telecoil Program.

Hearing loss can lead to isolation and social withdrawal. The telephone oftentimes connects persons with hearing loss to society; however, telephone use is impeded by narrow bandwidth, loss of visual cues, electromagnetic interference, and inherent phone-line noise. In the past, research assessing telephone communication has consistently reported that switching from the microphone to a telecoil will typically result in the acoustic signal being discernibly softer. Properly used telecoils improve the signal-to-noise ratio (SNR), decrease the chance for acoustic feedback, and overcome the impact of distance and reverberation creating an opportunity for clearer telephone communication. Little research, however, has examined matching the telecoil frequency response to the prescribed target of the microphone frequency response (National Acoustics Laboratories, Non-Linear, version 1 [NAL-NL1]). The primary goal of this study was to determine if differences exist in speech recognition for sentences (AZ-BIO) and consonant-vowel nucleus-consonant monosyllabic words (CNC) between two telecoil conditions (default and programmed). A secondary goal was to determine if differences exist in speech recognition for sentences between male and female talkers. A single-blinded randomized controlled trial. Twenty experienced adult hearing aid users with bilateral symmetric slight to severe sensorineural hearing loss were recruited from Washington University in St. Louis School of Medicine. In addition, ten normal-hearing participants were recruited to determine the presentation level of the speech stimuli for the hearing aid participants. Participants underwent real-ear measures to program the microphone frequency response of a receiver-in-the-canal hearing aid to NAL-NL1. Using the manufacturer software, one telecoil program remained as the manufacturer default and a second telecoil program was programmed so the sound pressure level for an inductive telephone simulator frequency response matching the microphone's frequency response to obtain as close to a 0 dB relative simulated equivalent telephone sensitivity value as possible. Participants then completed speech recognition measures including AZ-BIO sentences (male and female talkers) and CNC monosyllabic words and phonemes, using both telecoil programs. A mixed model analysis was performed to examine if significant differences in speech recognition exist between the two conditions and speech stimuli. Results revealed significant improvement in overall speech recognition for the programmed telecoil performance compared with default telecoil performance (p < 0.001). Also, improved performance in the programmed telecoil was reported with a male talker (p < 0.001) and performance for sentences compared with monosyllabic words (p < 0.001) or phonemes (p < 0.001). The programmed telecoil condition revealed significant improvement in speech recognition for all speech stimuli conditions compared with the default telecoil (sentences, monosyllables, and phonemes). Additional improvement was observed in both telecoil conditions when the talker was male.

The S-SH Confusion Test and the Effects of Frequency Lowering.

Purpose Frequency lowering in hearing aids can cause listeners to perceive [s] as [ʃ]. The S-SH Confusion Test, which consists of 66 minimal word pairs spoken by 6 female talkers, was designed to help clinicians and researchers document these negative side effects. This study's purpose was to use this new test to evaluate the hypothesis that these confusions will increase to the extent that low frequencies are altered. Method Twenty-one listeners with normal hearing were each tested on 7 conditions. Three were control conditions that were low-pass filtered at 3.3, 5.0, and 9.1 kHz. Four conditions were processed with nonlinear frequency compression (NFC): 2 had a 3.3-kHz maximum audible output frequency (MAOF), with a start frequency (SF) of 1.6 or 2.2 kHz; 2 had a 5.0-kHz MAOF, with an SF of 1.6 or 4.0 kHz. Listeners' responses were analyzed using concepts from signal detection theory. Response times were also collected as a measure of cognitive processing. Results Overall, [s] for [ʃ] confusions were minimal. As predicted, [ʃ] for [s] confusions increased for NFC conditions with a lower versus higher MAOF and with a lower versus higher SF. Response times for trials with correct [s] responses were shortest for the 9.1-kHz control and increased for the 5.0- and 3.3-kHz controls. NFC response times were also significantly longer as MAOF and SF decreased. The NFC condition with the highest MAOF and SF had statistically shorter response times than its control condition, indicating that, under some circumstances, NFC may ease cognitive processing. Conclusions Large differences in the S-SH Confusion Test across frequency-lowering conditions show that it can be used to document a major negative side effect associated with frequency lowering. Smaller but significant differences in response times for correct [s] trials indicate that NFC can help or hinder cognitive processing, depending on its settings.

The role of gender expectations on word recognition

Socio-indexical and linguistic information bi-directionally interact during speech processing. Information about a speaker’s age, gender, or ethnicity, conveyed through speech or visual cues, can influence how acoustic-phonetic cues are mapped to phoneme categories. For example, in McGowan (2015), Chinese-accented English sentences were presented along with a Chinese face (congruent), Caucasian face (incongruent), or no detailed visual information. Intelligibility scores were significantly higher in the congruent than the incongruent condition. Here, we investigate whether similar effects are observed for talker gender. Participants orthographically transcribed sentences mixed with noise from native American English male and female talkers. A gender congruent or incongruent visual face prime was presented before each sentence. In a control condition, different participants completed the task without the inclusion of visual face primes. Results showed that female talkers were significantly more intelligible than male talkers. Further, a gender congruency benefit was observed for female talkers, but not for male talkers. No incongruency cost was found; intelligibility scores in the incongruent and no-face control conditions did not differ. Although congruency effects were only observed with female talkers, the results suggest that expectations about speaker gender can influence word recognition accuracy similar to previously reported ethnicity effects.

Effects of aging on voice emotion recognition in cochlear implant users and normally hearing adults listening to spectrally degraded speech

Voice emotion recognition declines with age in normally hearing (NH) adults. However, the effects of aging on voice emotion recognition in NH listeners with spectrally degraded stimuli are neither known nor the effects of aging on adult cochlear implant (CI) users. This study explored age-related effects on voice emotion recognition in NH adults listening to spectrally degraded speech and aimed to compare these changes to age-related changes in adult CI users’ voice emotion recognition with unprocessed speech. Participants listened to 12 emotion-neutral sentences, each spoken with 5 emotions (happy, sad, scared, angry, and neutral) by a male and female talker. Participants identified which emotion they heard while listening to sentences that were either unprocessed or CI-simulated. Preliminary results indicate declines in overall percent correct scores and increased reaction time with both age and increasing spectral degradation in NH adults. Results also suggest age-related effects on percent correct scores and reaction times within the CI group alone. These results have important implications in the aging population of adults with NH and with CIs because limitations in the quality peer to peer interactions have been associated with a decrease in perceived quality of life. [Work supported by R01 DC014233 and P20 GM109023.]Voice emotion recognition declines with age in normally hearing (NH) adults. However, the effects of aging on voice emotion recognition in NH listeners with spectrally degraded stimuli are neither known nor the effects of aging on adult cochlear implant (CI) users. This study explored age-related effects on voice emotion recognition in NH adults listening to spectrally degraded speech and aimed to compare these changes to age-related changes in adult CI users’ voice emotion recognition with unprocessed speech. Participants listened to 12 emotion-neutral sentences, each spoken with 5 emotions (happy, sad, scared, angry, and neutral) by a male and female talker. Participants identified which emotion they heard while listening to sentences that were either unprocessed or CI-simulated. Preliminary results indicate declines in overall percent correct scores and increased reaction time with both age and increasing spectral degradation in NH adults. Results also suggest age-related effects on percent correct sco...

Talker head orientation discrimination using only auditory cues

Although many studies focus on human ability to localize a sound source, less is known about human ability to determine the physical orientation of a given sound source. In our study, we assessed listeners’ ability to detect changes in talker head orientation. Participants with normal hearing were asked to detect head orientation changes (relative to 0 deg, i.e., directly facing the listener) for two male and two female talkers. We found listeners are sensitive to changes of approximately 40 deg in talker head orientation using only auditory cues. This is less sensitive than what humans have displayed with only visual cues. These findings indicate that auditory cues are available for head orientation discrimination, which may be of greater utility when visual cues are unavailable.

Pitch accent and the three-way laryngeal contrast in North Kyungsang Korean

Previous description of Korean’s three-way voiceless stop contrast notes differentiation in both voice onset time (VOT) and fundamental frequency (f0) on following vowels (Cho et al., 2002; Kang and Han, 2013; Kang, 2014). In a sound-change in-progress, however, VOT for lenis and aspirated stops has merged. The two are now differentiated primarily through f0 differences (Kang and Guion, 2008; Lee et al., 2013; Silva, 2006). North and South Kyungsang (NK and SK) are pitch accent dialects. SK has not undergone the change (Lee and Jongman, 2012): VOT is still a primary cue, potentially because f0 is already used for the pitch accent system (Lee et al., 2013). In NK, meanwhile, VOT for lenis and aspirated stops overlaps more for female than for male speakers, suggesting a possible change-in-progress (Holliday and Kong, 2011). As questions about the robustness of this change remain, we report data from 23 native NK speakers (6 older and 6 younger males; 5 older and 6 younger females). VOT and f0 findings suggest that the new pattern is incipient in NK: Older male talkers show the old pattern, younger female talkers the new pattern, and older female and younger male talkers fall between the two extremes.

A Competing Voices Test for Hearing-Impaired Listeners Applied to Spatial Separation and Ideal Time-Frequency Masks.

People with hearing impairment find competing voices scenarios to be challenging, both with respect to switching attention from one talker to the other, as well as maintaining attention. With the Danish competing voices test (CVT) presented here, the dual-attention skills can be assessed. The CVT provides sentences spoken by three male and three female talkers, played in sentence pairs. The task of the listener is to repeat the target sentence from the sentence pair based on cueing either before or after playback. One potential way of assisting segregation of two talkers is to take advantage of spatial unmasking by presenting one talker per ear after application of time-frequency masks for separating the mixture. Using the CVT, this study evaluated four spatial conditions in 14 moderate-to-severely hearing-impaired listeners to establish benchmark results for this type of algorithm applied to hearing-impaired listeners. The four spatial conditions were as follows: summed (diotic), separate, the ideal ratio mask, and the ideal binary mask. The results show that the test is sensitive to the change in spatial condition. The temporal position of the cue has a large impact, as cueing the target talker before playback focuses the attention toward the target, whereas cueing after playback requires equal attention to the two talkers, which is more difficult. Furthermore, both applied ideal masks show test scores very close to the ideal separate spatial condition, suggesting that this technique is useful for future separation algorithms using estimated rather than ideal masks.

Infants' selective use of reliable cues in multidimensional language input.

Learning always happens from input that contains multiple structures and multiple sources of variability. Though infants possess learning mechanisms to locate structure in the world, lab-based experiments have rarely probed how infants contend with input that contains many different structures and cues. Two experiments explored infants' use of two naturally occurring sources of variability-different sounds and different people-to detect regularities in language. Monolingual infants (9-10 months) heard a male and female talker produce two different speech streams, one of which followed a deterministic pattern (e.g., AAB, le-le-di) and one of which did not. For half of the infants, each speaker produced only one of the streams; for the other half of the infants, each speaker produced 50% of each stream. In Experiment 1, each stream consisted of distinct sounds, and infants successfully demonstrated learning regardless of the correspondence between speaker and stream. In Experiment 2, each stream consisted of the same sounds, and infants failed to show learning, even when speakers provided a perfect cue for separating each stream. Thus, monolingual infants can learn in the presence of multiple speech streams, but these experiments suggest that infants may rely more on sound-based rather than speaker-based distinctions when breaking into the structure of incoming information. This selective use of some cues over others highlights infants' ability to adaptively focus on distinctions that are most likely to be useful as they sort through their inherently multidimensional surroundings. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Are there sex effects for speech intelligibility in American English? Examining the influence of talker, listener, and methodology.

Talker and listener sex in speech processing has been largely unknown and under-appreciated to this point, with many studies overlooking the possible influences. In the current study, the effects of both talker and listener sex on speech intelligibility were assessed. Different methodological approaches to measuring intelligibility (percent words correct vs. subjective rating scales) and collecting data (laboratory vs. crowdsourcing) were also evaluated. Findings revealed that, regardless of methodology, the spoken productions of female talkers were overall more intelligible than the spoken productions of male talkers; however, substantial variability across talkers was observed. Findings also revealed that when data were collected in the lab, there was an interaction between talker and listener sex. This interaction between listener and talker sex was not observed when subjective ratings were crowdsourced from listener subjects across the USA via Amazon Mechanical Turk, although overall ratings remained similar. This possibly suggests that subjective intelligibility ratings may be vulnerable to bias, and such biases may be reduced by recruiting a more heterogeneous subject pool. Many studies in speech perception do not account for these talker, listener, and methodology effects. However, the present results suggest that researchers should carefully consider these effects when assessing speech intelligibility in different conditions, and when comparing findings across studies that have used different subject demographics and/or methodologies.

Infants use onset asynchrony cues in auditory scene analysis.

This experiment investigated the effect of onset asynchrony on the segregation of concurrent vowels in infants and adults. Two vowels, randomly chosen from seven American-English vowels, were superimposed. Each vowel pair contained one vowel by a male and one by a female talker. A train of such vowel pairs was presented to listeners, who were trained to respond to the male target vowel /i:/ or /u:/. The ability to identify the target vowel was compared among three conditions: synchronous onset, 100-, and 200-ms onset asynchrony. Experiment 1 measured performance, in d', in 7-month-old infants and adults. Infants and adults performed better with asynchronous than synchronous vowel onset, regardless of asynchrony duration. Experiment 2 compared the proportion of 3-month-old infants achieving an 80% correct criterion with and without onset asynchrony. Significantly more infants reached criterion with asynchronous than with synchronous vowel onset. Asynchrony duration did not influence performance. These experiments show that infants, as young as 3 months old, benefit from onset asynchrony.

Developmental Effects in Masking Release for Speech-in-Speech Perception Due to a Target/Masker Sex Mismatch.

The purpose of this study was to evaluate the extent to which infants, school-age children, and adults benefit from a target/masker sex mismatch in the context of speech detection or recognition in a background of 2 competing talkers. It was hypothesized that the ability to benefit from a target/masker sex mismatch develops between infancy and the early school-age years, as children gain listening experience in multi-talker environments. Listeners were infants (7 to 13 months), children (5 to 10 years), and adults (18 to 33 years) with normal hearing. A series of five experiments compared speech detection or recognition in continuous two-talker speech across target/masker conditions that were sex matched or sex mismatched. In experiments 1 and 2, an observer-based, single-interval procedure was used to estimate speech detection thresholds for a spondaic word in a two-talker speech masker. In experiments 3 and 4, speech recognition thresholds were estimated in continuous two-talker speech using a four-alternative, forced-choice procedure. In experiment 5, speech reception thresholds (SRTs) were estimated for adults using the forced-choice recognition procedure after ideal time-frequency segregation processing was applied to the stimuli. Speech detection thresholds for adults tested in experiments 1 and 2 were significantly higher when the target word and speech masker were matched in sex than when they were mismatched, but thresholds for infants were similar across sex-matched and sex-mismatched conditions. Results for experiments 3 and 4 showed that school-age children and adults benefit from a target/masker sex mismatch for a forced-choice word recognition task. Children, however, obtained greater benefit than adults in 1 condition, perhaps due to greater susceptibility to masking overall. In experiment 5, adults had substantial threshold reductions and more uniform performance across the 4 conditions evaluated in experiments 3 and 4 after the application of ideal time-frequency segregation to the stimuli. The pattern of results observed across experiments suggests that the ability to take advantage of differences in vocal characteristics typically found between speech produced by male and female talkers develops between infancy and the school-age years. Considerable child-adult differences in susceptibility to speech-in-speech masking were observed for school-age children as old as 11 years of age in both sex-matched and sex-mismatched conditions.

Perception of talker height and sex from children’s voices

Several recent studies have investigated the ability of listeners to judge the height of adult talkers from their speech. Here, we examine the perception of talker height from a sample of /hVd/ syllables spoken by children ranging in age from 5 through 18 years, with 3 talkers of each sex at each age level. Twenty college students judged the height and sex of the talker for each trial. Perceptual estimates of height were moderately correlated with actual height (for males, r = 0.78; for females, r = 0.67). Consistent with our recent findings concerning the perception of talker age [Barreda &amp; Assmann, JASA-EL 143(5), EL361, 2018], listeners' judgments of talker height appear to incorporate assumptions about talker sex and the relationships between speech acoustics and veridical height for male and female talkers of different heights. For example, when older girls were misidentified as boys, their height was likely to be underestimated. This behavior results in predictable error patterns in height judgments from speech: in situations where talker sex is misidentified, listeners apply the “wrong” acoustic model to estimate talker height, leading to correlated error patterns between apparent height and sex.

Gender, the individual, and intelligibility

In the clinic and in the laboratory, opinions differ on the relative intelligibility of the speech of women and men. However, the effect of gender alone has rarely been studied explicitly. Here we present a study of 30 talkers (15 male) and 32 listeners assessing intelligibility of a 180-sentence subset of the IEEE sentences presented in steady-state speech-shaped noise. Four signal-to-noise ratios (−4, −2, 0, + 2 dB SNR) were tested with 45 sentences each. Results showed substantial overlap between intelligibility scores for each gender. Although standard statistical approaches show a slight advantage for female talkers at all SNRs, post-hoc analyses indicated that the gender effect is an artifact driven by a few particularly unintelligible males. These results do not address intrinsic gender-related differences in speech intensity, or in the ability to overcome background noise by speaking clearly, but suggest that gender-related differences are negligible when those factors are controlled. More generally, even with a large sample of talkers, the high degree of talker-intrinsic variability in intelligibility can lead to conclusions that do not generalize to the population of interest, an issue that could affect comparisons rooted in gender, dialect, or other social factors.

The effect of reward on listening effort as reflected by the pupil dilation response

Listening to speech in noise can be effortful but when motivated people seem to be more persevering. Previous research showed effects of monetary reward on autonomic responses like cardiovascular reactivity and pupil dilation while participants processed auditory information. The current study examined the effects of monetary reward on the processing of speech in noise and related listening effort as reflected by the pupil dilation response. Twenty-four participants (median age 21 yrs) performed two speech reception threshold (SRT) tasks, one tracking 50% correct (hard) and one tracking 85% correct (easy), both of which they listened to and repeated sentences uttered by a female talker. The sentences were presented with a single male talker or, in a control condition, in quiet. Participants were told that they could earn a high (5 euros) or low (0.20 euro) reward when repeating 70% or more of the sentences correctly. Conditions were presented in a blocked fashion and during each trial, pupil diameter was recorded. At the end of each block, participants rated the effort they had experienced, their performance, and their tendency to quit listening. Additionally, participants performed a working memory capacity task and filled in a need-for-recovery questionnaire as these tap into factors that influence the pupil dilation response. The results showed no effect of reward on speech perception performance as reflected by the SRT. The peak pupil dilation showed a significantly larger response for high than for low reward, for the easy and hard conditions, but not the control condition. Higher need for recovery was associated with a higher subjective tendency to quit listening. Consistent with the Framework for Understanding Effortful Listening, we conclude that listening effort as reflected by the peak pupil dilation is sensitive to the amount of monetary reward.

LiCoS: A New Linguistically Controlled Sentences Test to Assess Functional Hearing Performance

Purpose: To overcome the potential tension between clinical and ecological validity in speech audiometric assessment by creating a new set of sentence materials with high linguistic validity for the Dutch-speaking area. Methods: A linguistic “fingerprint” of modern spoken Dutch and Flemish served to generate a set of sentences recorded from 1 male and 1 female talker. The sentences were presented to 30 normal-hearing listeners in stationary speech noise at a signal-to-noise ratio (SNR) of –5 dB sound pressure level (SPL). A list design criterion was used to achieve perceptive homogeneity across the test lists, by scrambling lists of sentences of different syntactic types while controlling for linguistic complexity. The original set of test materials was narrowed down to 360 sentences, and list equivalency was evaluated at the audiological and linguistic levels. A psychometric curve was generated with a resolution of 2 dB based on a second group of 60 young normal-hearing native speakers of Dutch and Flemish. Results: Sentence understanding showed an average repetition accuracy of 63.40% (SD 1.01) across the lists at an SNR of –5 dB SPL. No significant differences were found between the lists at the level of the individual listener. At the linguistic level, the sentence lists showed an equal distribution of phonological, morphological, and syntactic features. Conclusion: LiCoS combines the clinical benefit of acoustic control at the list level with the high ecological validity of linguistically representative test items. The new speech audiometric test is particularly appropriate to assess sentence understanding in individuals who would otherwise exhibit near-ceiling performance when tested with linguistically more simplified test stimuli. In combination with pure tone audiometric assessment, LiCoS provides valuable complementary information with respect to the functional hearing of patients.

Factors Affecting Speech Reception in Background Noise with a Vocoder Implementation of the FAST Algorithm.

Speech segregation in background noise remains a difficult task for individuals with hearing loss. Several signal processing strategies have been developed to improve the efficacy of hearing assistive technologies in complex listening environments. The present study measured speech reception thresholds in normal-hearing listeners attending to a vocoder based on the Fundamental Asynchronous Stimulus Timing algorithm (FAST: Smith et al. 2014), which triggers pulses based on the amplitudes of channel magnitudes in order to preserve envelope timing cues, with two different reconstruction bandwidths (narrowband and broadband) to control the degree of spectrotemporal resolution. Five types of background noise were used including same male talker, female talker, time-reversed male talker, time-reversed female talker, and speech-shaped noise to probe the contributions of different types of speech segregation cues and to elucidate how degradation affects speech reception across these conditions. Maskers were spatialized using head-related transfer functions in order to create co-located and spatially separated conditions. Results indicate that benefits arising from voicing and spatial cues can be preserved using the FAST algorithm but are reduced with a reduction in spectral resolution.

A comparison of phonetic convergence in conversational interaction and speech shadowing

Phonetic convergence is a form of variation in speech production in which a talker adopts aspects of another talker’s acoustic–phonetic repertoire. To date, this phenomenon has been investigated in non-interactive laboratory tasks extensively and in conversational interaction to a lesser degree. The present study directly compares phonetic convergence in conversational interaction and in a non-interactive speech shadowing task among a large set of talkers who completed both tasks, using a holistic AXB perceptual similarity measure. Phonetic convergence occurred in a new role-neutral conversational task, exhibiting a subtle effect with high variability across talkers that is typical of findings reported in previous research. Conversational phonetic convergence did not differ by talker sex on average, but relationships between speech shadowing and conversational convergence differed according to talker sex, with female talkers showing no consistency across settings in their relative levels of convergence and male talkers showing a modest relationship. These findings indicate that phonetic convergence is not directly compatible across different settings, and that phonetic convergence of female talkers in particular is sensitive to differences across different settings. Overall, patterns of acoustic–phonetic variation and convergence observed both within and between different settings of language use are inconsistent with accounts of automatic perception-production integration.

Infants' use of amplitude modulation cues in the segregation of concurrent vowels

Infants have difficulties separating speech from competing sounds. One explanation is that infants do not use acoustic cues to sound source segregation as adults do. This study investigated 3- and 7-month-old infants’ and adults’ ability to use AM cues in concurrent vowel segregation. Seven American-English vowels were produced by a male and by a female talker. One male and one female vowel were randomly chosen and superimposed. A train of such vowel pairs was presented to listeners, who were trained to respond to the male target vowel /i:/ or /u:/. Target-to-nontarget ratios were chosen to equate performance across age groups. In the baseline condition, all vowels had flat envelopes. In the cue condition, male vowels were modulated with three envelopes from infant-directed vowels. The proportion of 3-month-old infants achieving an 80% correct criterion at a ratio of + 15dB was higher in the cue than in the baseline condition. For 7-month olds and adults d' could be estimated based on 15 target and 15 nontarget trials in each condition. Preliminary results indicate that both 7-month-old infants and adults have a higher d' in the cue than in the baseline condition. Thus, infants appear to use AM to segregate concurrent vowels.

Children’s ability to benefit from fundamental frequency and vocal tract length differences during speech-in-speech recognition

The present study evaluated whether children’s speech-in-speech recognition benefits from differences in fundamental frequency (F0) or vocal tract length (VTL) between the target and masker talkers’ voices. Children, like adults, can benefit from a sex mismatch between competing talkers, but the relative contribution of individual voice characteristics to children’s improved speech-in-speech understanding is unknown. In this study, we first tested children’s ability to use differences in either F0 or VTL between target and masker speech to evaluate the independent influence of these cues on speech-in-speech recognition. Then F0 and VTL differences were combined to determine whether cue redundancy would reduce the child/adult differences observed in these contexts. Sentence recognition thresholds were measured in a two-talker speech masker. All stimuli were recorded by the same female talker. F0 and VTL of the target sentences were manipulated using the pitch-synchronous overlap-add method. Preliminary results suggest a prolonged developmental trajectory in the ability to use F0 or VTL in isolation, but indicate that the combination of these cues benefits children at an earlier age compared to when either cue is presented in isolation. Adults showed the greatest benefit from the F0-only manipulation, showing no additional benefit when F0 and VTL were combined.

The effect of clear speech on listener perception of nonnative speech

Listener perception of nonnative speech may be measured as intelligibility, ease of understanding, or accentedness. The relationship among these variables is complex, as is the influence of clear speech on these measures. The purpose of this study was to explore the effect on listener perception of clear speech produced by Spanish-accented talkers of American English. Specifically, four questions guided this study: Does clear speech enhance intelligibility and ease of understanding? What is the effect of clear speech on accentedness? How does speaking style (conversational versus clear) influence the relationship among these perceptual variables? Does the presence or absence of supporting contextual information modify the relationship among intelligibility, ease of understanding, and accentedness? Twenty-eight female talkers of American English (half native English-speaking and half Spanish-accented) read aloud 56 short sentences using conversational and clear speech. The 56 sentences were comprised of 28 pairs, each containing a high- or low-probability final word. Young, normal-hearing, monolingual English listeners transcribed and rated ease of understanding for sentences presented in 12-talker babble, and then rated accentedness for sentences presented in quiet. Listeners assigned ratings using visual analog scales. Results and their implications for models of listener perception and clinical management of accentedness will be discussed.