Masking Conditions Research Articles

Are Acoustic Markers of Voice and Speech Signals Affected by Nose-and-Mouth-Covering Respiratory Protective Masks?

BackgroundWorldwide use of nose-and-mouth-covering respiratory protective mask (RPM) has become ubiquitous during COVID19 pandemic. Consequences of wearing RPMs, especially regarding perception and production of spoken communication, are gradually emerging. The present study explored how three prevalent RPMs affect various speech and voice sound properties.MethodsPre-recorded sustained [a] vowels and read sentences from 47 subjects were played by a speech production model (‘Voice Emitted by Spare Parts’, or ‘VESPA’) in four conditions: without RPM (C1), with disposable surgical mask (C2), with FFP2 mask (C3), and with transparent plastic mask (C4). Differences between C1 and masked conditions were assessed with Dunnett's t test in 26 speech sound properties related to voice production (fundamental frequency, sound intensity level), voice quality (jitter percent, shimmer percent, harmonics-to-noise ratio, smoothed cepstral peak prominence, Acoustic Voice Quality Index), articulation and resonance (first and second formant frequencies, first and second formant bandwidths, spectral center of gravity, spectral standard deviation, spectral skewness, spectral kurtosis, spectral slope, and spectral energy in ten 1-kHz bands from 0 to 10 kHz).ResultsC2, C3, and C4 significantly affected 10, 15, and 19 of the acoustic speech markers, respectively. Furthermore, absolute differences between unmasked and masked conditions were largest for C4 and smallest for C2.ConclusionsAll RPMs influenced more or less speech sound properties. However, this influence was least for surgical RPMs and most for plastic RPMs. Surgical RPMs are therefore preferred when spoken communication is priority next to respiratory protection.

The concealment of accelerated information is possible

The possibility of masking an accelerated two-qubit system by using a minimum number of qubits is discussed. It is shown that the information may be masked in either entangled local states or product non-local separable states. We examine that each partition of these states satisfies the masking conditions. Due to the presence of non-local separable partition, one may consider that it is a type of quantum data hiding scheme. The local/non-local information encoded in the masked entangled state is robust against the decoherence of the acceleration process. The possibility of estimating the acceleration parameter via the entangled/separable masked state increases as the initial entanglement value increases. The efficiency of the masking process is examined by quantifying the fidelity of the accelerated state and its subsystems. It is shown that the fidelity of the masked state is maximum at small initial acceleration, while the minimum fidelity is more than 96%.

Informational Masking Effects of Similarity and Uncertainty on Early and Late Stages of Auditory Cortical Processing

Understanding speech in a background of other people talking is a difficult listening situation for hearing-impaired individuals, and even for those with normal hearing. Speech-on-speech masking is known to contribute to increased perceptual difficulty over nonspeech background noise because of informational masking provided over and above the effects of energetic masking. While informational masking research has identified factors of similarity and uncertainty between target and masker that contribute to reduced behavioral performance in speech background noise, critical gaps in knowledge including the underlying neural-perceptual processes remain. By systematically manipulating aspects of acoustic similarity and uncertainty in the same auditory paradigm, the current study examined the time course and objectively quantified these informational masking effects at both early and late stages of auditory processing using auditory evoked potentials (AEPs). Thirty participants were included in a cross-sectional repeated measures design. Target-masker similarity was manipulated by varying the linguistic/phonetic similarity (i.e., language) of the talkers in the background. Specifically, four levels representing hypothesized increasing levels of informational masking were implemented: (1) no masker (quiet); (2) Mandarin; (3) Dutch; and (4) English. Stimulus uncertainty was manipulated by task complexity, specifically presentation of target-to-target interval (TTI) in the auditory evoked paradigm. Participants had to discriminate between English word stimuli (/bæt/ and /pæt/) presented in an oddball paradigm under each masker condition pressing buttons to either the target or standard stimulus. Responses were recorded simultaneously for P1-N1-P2 (standard waveform) and P3 (target waveform). This design allowed for simultaneous recording of multiple AEP peaks, as well as accuracy, reaction time, and d' behavioral discrimination to button press responses. Several trends in AEP components were consistent with effects of increasing linguistic/phonetic similarity and stimulus uncertainty. All babble maskers significantly affected outcomes compared to quiet. In addition, the native language English masker had the largest effect on outcomes in the AEP paradigm, including reduced P3 amplitude and area, as well as decreased accuracy and d' behavioral discrimination to target word responses. AEP outcomes for the Mandarin and Dutch maskers, however, were not significantly different across any measured component. Latency outcomes for both N1 and P3 also supported an effect of stimulus uncertainty, consistent with increased processing time related to greater task complexity. An unanticipated result was the absence of the interaction of linguistic/phonetic similarity and stimulus uncertainty. Observable effects of both similarity and uncertainty were evidenced at a level of the P3 more than the earlier N1 level of auditory cortical processing suggesting that higher-level active auditory processing may be more sensitive to informational masking deficits. The lack of significant interaction between similarity and uncertainty at either level of processing suggests that these informational masking factors operated independently. Speech babble maskers across languages altered AEP component measures, behavioral detection, and reaction time. Specifically, this occurred when the babble was in the native/same language as the target, while the effects of foreign language maskers did not differ. The objective results from this study provide a foundation for further investigation of how the linguistic content of target and masker and task difficulty contribute to difficulty understanding speech-in-noise.

Systematic Comparison of Trial Exclusion Criteria for Pupillometry Data Analysis in Individuals With Single-Sided Deafness and Normal Hearing.

The measurement of pupil dilation has become a common way to assess listening effort. Pupillometry data are subject to artifacts, requiring highly contaminated data to be discarded from analysis. It is unknown how trial exclusion criteria impact experimental results. The present study examined the effect of a common exclusion criterion, percentage of blinks, on speech intelligibility and pupil dilation measures in 9 participants with single-sided deafness (SSD) and 20 participants with normal hearing. Participants listened to and repeated sentences in quiet or with speech maskers. Pupillometry trials were processed using three levels of blink exclusion criteria: 15%, 30%, and 45%. These percentages reflect a threshold for missing data points in a trial, where trials that exceed the threshold are excluded from analysis. Results indicated that pupil dilation was significantly greater and intelligibility was significantly lower in the masker compared with the quiet condition for both groups. Across-group comparisons revealed that speech intelligibility in the SSD group decreased significantly more than the normal hearing group from quiet to masker conditions, but the change in pupil dilation was similar for both groups. There was no effect of blink criteria on speech intelligibility or pupil dilation results for either group. However, the total percentage of blinks in the masker condition was significantly greater than in the quiet condition for the SSD group, which is consistent with previous studies that have found a relationship between blinking and task difficulty. This association should be carefully considered in future experiments using pupillometry to gauge listening effort.

Forward masking with frequency-following response analyses

Purpose: to analyze forward masking in normally hearing young people, by using frequency-following responses. Methods: the synthetic syllable /da/ was used for the recordings of ten individuals, in the following conditions: /da/ with no masking, and /da/ after 4, 16, 32, and 64 milliseconds of masking. F-test (ANOVA) was applied for repeated measures with the Greenhouse-Geisser correction to compare testing conditions. For significant differences, multiple comparisons (between pairs of conditions) and Bonferroni correction were used. Data normality was verified by applying the Shapiro-Wilk test, and statistical significance was used at 5%. Results: wave latencies of all masking conditions were compared with those of no masking. A latency delay was observed in the transient region of the response (PV and A) in all masking conditions, except for 64 milliseconds. Latency delay also occurred for waves PW, PX, and PY, which corresponded to the sustained region of the response. Conclusion: forward masking was observed, by using frequency-following responses with /da/ syllable in four intervals (4, 16, 32, and 64 ms) of preceding masking. Forward masking was more evident in the transient region of the response than in the sustained one. This study highlights the importance of electrophysiological testing in temporal processing assessment.

Subliminal affective priming effect: Dissociated processes for intense versus normal facial expressions

Positive vs. negative intense-facial expressions are difficult to explicitly distinguish; yet, whether they dissociate when subliminally presented remains unclear. Through three experiments using affective priming paradigms, we assessed how intense facial expressions, when presented briefly (17 ms) and masked, influenced following neutral ambiguous words (Experiment 1) or visible facial expressions (Experiments 2&3). We also compared these results with those of using normal facial expressions as primes in each experiment. All experiments indicated masked affective priming effects (biasing valence judgement of neutral words or facilitating reaction time to faces with the same valence as the prime) in normal facial expression, but not those intense ones. Experiment 3 using event related potentials (ERPs) further revealed that two ERP components N250 and LPP were consistent with behavioral changes in the normal condition (larger when valences of primes and targets were different), but inconsistent in the intense condition. Taken together, our results provided behavioral and neural evidence for distinctive processing between normal and intense facial expressions under masked condition.

Evaluating Automated Face Identity-Masking Methods with Human Perception and a Deep Convolutional Neural Network

Face de-identification (or “masking”) algorithms have been developed in response to the prevalent use of video recordings in public places. We evaluated the success of face identity masking for human perceivers and a deep convolutional neural network (DCNN). Eight de-identification algorithms were applied to videos of drivers’ faces, while they actively operated a motor vehicle. These masks were pre-selected to be applicable to low-quality video and to maintain coarse information about facial actions. Humans studied high-resolution images to learn driver identities and were tested on their recognition of active drivers in low-resolution videos. Faces in the videos were either unmasked or were masked by one of the eight algorithms. When participants were tested immediately after learning (Experiment 1), all masks reduced identification, with six of eight masks reducing identification to extremely poor performance. In a second experiment, two of the most effective masks were tested after a delay of 7 or 28 days. The delay did not further reduce identification of the masked faces. In all masked conditions, participants maintained stringent decision criteria, with low confidence in recognition, further indicating the effectiveness of the masks. Next, the DCNN performed an identity-matching task between high-resolution images and masked videos—a task analogous to that done by humans. The pattern of accuracy for the DCNN mirrored some, but not all, aspects of human performance, highlighting the need to test the effectiveness of identity masking for both humans and machines. The DCNN was also tested on its ability to match identity between masked and unmasked versions of the same video, based only on the face. DCNN performance for the eight masks offers insight into the nature of the information in faces that is coded in these networks.

Interocular Suppression as Revealed by Dichoptic Masking Is Orientation-Dependent and Imbalanced in Amblyopia.

PurposeWe investigate the orientation tuning of interocular suppression using a dichoptic masking paradigm in adult controls and amblyopes.MethodsFourteen adults with anisometropic or mixed amblyopia and 10 control adults participated in our study. Contrast sensitivity was measured by presenting a target Gabor in the tested eye and mean luminance in the untested eye (monocular) and by presenting a target in the tested eye and a bandpass oriented filtered noise in the other eye (masked). Interocular suppression was defined as the thresholds difference between the monocular and masked conditions for each eye. Interocular suppression was measured under parallel and orthogonal suppression configurations. The peak spatial frequency of the target and mask was 0.25 c/d in experiment 1 (low), 1.31 c/d in experiment 2 (mid), and 6.87 c/d in experiment 3 (high).ResultsThe masking suppression induced by the amblyopic eye was less strong than that induced by the fellow eye. The suppression from the fellow eye was similar to that observed in the controls. Interocular suppression under parallel configuration was less strong than under orthogonal configuration in amblyopes at low and mid spatial frequency, but not at high spatial frequency.ConclusionsWe demonstrate that the abnormal interocular masking in amblyopia displays the expected characteristic of orientation selectivity expected of normal controls at low and mid spatial frequency, but not at high spatial frequency. The dichoptic masking imbalance between the eyes of amblyopes results in a net suppression of the amblyopic eye during binocular viewing, modeling clinical suppression.

Dyslexia and the magnocellular-parvocellular coactivaton hypothesis

Previous studies showed that the lateral masking of a fast-moving low spatial frequency (SF) target was strong when exerted by static flankers of lower or equal to the target SF and absent when flankers’ SF was higher than the target’s one. These masking and unmasking effects have been interpreted as due to Magnocellular-Magnocellular (M-M) inhibition and Parvocellular-on-Magnocellular (P-M) disinhibitory coactivation, respectively. Based on the hypothesis that the balance between the two systems is perturbed in Developmental Dyslexia (DD), we asked whether dyslexic children (DDs) behaved differently than Typically Developing children (TDs) in conditions of lateral masking. DDs and TDs performed a motion discrimination task, of a .5c/deg Gabor target moving at 16 deg/sec, either isolated or flanked by static Gabors with a SF of .125, .5 or 2 c/deg (Experiment 1). As a control, they also performed a contrast detection task of a static target, either isolated or flanked (Experiment 2). DDs did not perform any different from TDs with either a static target or an isolated moving target of low spatial frequency, thus suggesting efficient feedforward Magnocellular (M) and Parvocellular (P) processing. Also, DDs showed similar contrast thresholds to TDs in the M-M inhibition condition. Conversely, DDs did not recover from lateral masking in the M-P coactivation condition. In addition, their performance in this condition negatively correlated with non-words accuracy, supporting the suggestion that an inefficient Magno-Parvo coactivation may possibly be associated to both higher visual suppression and reduced perceptual stability during reading.

Spatial Release From Masking in Bimodal and Bilateral Pediatric Cochlear Implant Recipients.

Purpose Traditional clinical measures of cochlear implant (CI) recipient performance may not fully evaluate the benefit of bimodal listening (hearing aid contralateral to a CI). The clinical assessment of spatial release from masking (SRM) may be a sensitive measure of the benefit of listening with bimodal stimulation. This study compared the SRM of pediatric bimodal and bilateral CI listeners using a clinically feasible method, and investigated variables that may contribute to speech recognition performance with spatially separated maskers. Method Forty pediatric bimodal (N = 20) and bilateral CI (N = 20) participants were assessed in their best aided listening condition on sentence recognition in a four-talker masker. Testing was completed with target and masker colocated at 0° azimuth, and with the masker directed at 90° to either ear. SRM was calculated as the difference in performance between the colocated and each 90° condition. A two-way mixed-methods analysis of variance was used to compare performance between groups in the three masker conditions. Multiple regression analyses were conducted to investigate potential predictors for SRM asymmetry including hearing history, unaided thresholds, word recognition, duration of device use, and acoustic bandwidth. Results Both groups demonstrated SRM, with significantly better recognition in each 90° condition as compared to the colocated condition. The groups did not differ significantly in SRM. The multiple regression analyses did not reveal any significant predictors of SRM asymmetry. Conclusions Bimodal and bilateral CI listeners demonstrated similar amounts of SRM. While no specific variables predicted SRM asymmetry in bimodal listeners, pediatric bimodal and bilateral CI recipients should expect similar amounts of SRM regardless of the side of the masker. SRM asymmetry in pediatric bimodal listeners may signal a need for consideration of a second CI.

Enhancing the perceptual segregation and localization of sound sources with a triple beamformer.

A triple beamformer was developed to exploit the capabilities of the binaural auditory system. The goal was to enhance the perceptual segregation of spatially separated sound sources while preserving source localization. The triple beamformer comprised a variant of a standard single-channel beamformer that routes the primary beam output focused on the target source location to both ears. The triple beam algorithm adds two supplementary beams with the left-focused beam routed only to the left ear and the right-focused beam routed only to the right ear. The rationale for the approach is that the triple beam processing exploits sound source segregation in high informational masking (IM) conditions. Furthermore, the exaggerated interaural level differences produced by the triple beam are well-suited for categories of listeners (e.g., bilateral cochlear implant users) who receive limited benefit from interaural time differences. The performance with the triple beamformer was compared to normal binaural hearing (simulated using a Knowles Electronic Manikin for Auditory Research, G.R.A.S. Sound and Vibration, Holte, DK) and to that obtained from a single-channel beamformer. Source localization in azimuth and masked speech identification for multiple masker locations were measured for all three algorithms. Taking both localization and speech intelligibility into account, the triple beam algorithm was considered to be advantageous under high IM listening conditions.

A New Dichoptic Training Strategy Leads to Better Cooperation Between the Two Eyes in Amblyopia.

Recent clinical trials failed to endorse dichoptic training for amblyopia treatment. Here, we proposed an alternative training strategy that focused on reducing signal threshold contrast in the amblyopic eye under a constant and high noise contrast in the fellow eye (HNC), and compared it to a typical dichoptic strategy that aimed at increasing the tolerable noise contrast in the fellow eye (i.e., TNC strategy). We recruited 16 patients with amblyopia and divided them into two groups. Eight patients in Group 1 received the HNC training, while the other eight patients in Group 2 performed the TNC training first (Phase 1) and then crossed over to the HNC training (Phase 2). We measured contrast sensitivity functions (CSFs) separately in the amblyopic and fellow eyes when the untested eye viewed mean luminance (monocularly unmasked) or noise stimuli (dichoptically masked) before and after training at a particular frequency. The area under the log contrast sensitivity function (AULCSF) of masked and unmasked conditions, and dichoptic gain (the ratio of AULCSF of masked to unmasked condition) were calculated for each eye. We found that both dichoptic training paradigms substantially improved masked CSF, dichoptic gain, and visual acuity in the amblyopic eye. As opposed to the TNC paradigm, the HNC training produced stronger effects on masked CSFs, stereoacuity, dichoptic gain, and visual acuity in the amblyopic eye. Interestingly, the second-phase HNC training in Group 2 also induced further improvement in the masked contrast sensitivity and AULCSF in the amblyopic eye. We concluded that the HNC training strategy was more effective than the TNC training paradigm. Future design for dichoptic training should not only focus on increasing the tolerable noise contrast in the fellow eye but should also “nurture” the amblyopic eye under normal binocular viewing conditions and sustained interocular suppression.

Assessing the benefit of acoustic beamforming for listeners with aphasia using modified psychoacoustic methods.

Acoustic beamforming has been shown to improve identification of target speech in noisy listening environments for individuals with sensorineural hearing loss. This study examined whether beamforming would provide a similar benefit for individuals with aphasia (acquired neurological language impairment). The benefit of beamforming was examined for persons with aphasia (PWA) and age- and hearing-matched controls in both a speech masking condition and a speech-shaped, speech-modulated noise masking condition. Performance was measured when natural spatial cues were provided, as well as when the target speech level was enhanced via a single-channel beamformer. Because typical psychoacoustic methods may present substantial experimental confounds for PWA, clinically guided modifications of experimental procedures were determined individually for each PWA participant. Results indicated that the beamformer provided a significant overall benefit to listeners. On an individual level, both PWA and controls who exhibited poorer performance on the speech masking condition with spatial cues benefited from the beamformer, while those who achieved better performance with spatial cues did not. All participants benefited from the beamformer in the noise masking condition. The findings suggest that a spatially tuned hearing aid may be beneficial for older listeners with relatively mild hearing loss who have difficulty taking advantage of spatial cues.

Release in linguistic masking changes over time: differences between native and non-native listeners

Research into speech-on-speech masking has identified what is known as release from linguistic masking, i.e., better speech transcription performance against a masker in an unknown than known language. To test whether native (English) and non-native (Mandarin) speakers of English could learn to control the interference of a known language masker, we measured their ability to transcribe English sentences against the background of English or Mandarin competing talkers over the course of 50 trials. Both groups improved over time. Native listeners exhibited release from linguistic masking, with less masking in the Mandarin than English masker condition. The size of this effect increased over time. In contrast, non-native listeners showed no difference between the two language maskers, with this pattern unaffected by time. Masker-to-target intrusion errors decreased over time for native listeners, whereas they were virtually absent for the non-native listeners. The results show that (1) Linguistic masking is worst when the masker language is known to the listener, whether that language is native or non-native, (2) Whether the masker is the same language as the target language is comparatively less important for non-native listeners, and (3) Native listeners are better at learning to suppress masker interference over time than non-native listeners.

Performance prediction of Building Integrated Photovoltaics under no-shading, shading and masking conditions using a multi-physics model

Under shading/masking conditions, electrical performance of Building Integrated Photovoltaic systems is always the emphasis of previous researches. But thermal and structural performance, which are essential for electrical prediction accuracy and lifespan of the system, are overlooked. This paper is the first to present a verified multi-physics model to predict the electrical, thermal and structural performance under no-shading, shading and masking conditions, as well as when the hot-spot occurs. Particularly, the model contains a simplified electrical mathematical model that is capable of simulating the power output of PV systems under shading conditions and under masking conditions in one expression. Furthermore, the thermal model results have been compared with temperature distributions of the PV module in a full scale with maximum 0.8 °C root mean square error. Using the developed model, it is shown that differentiating shading condition and masking condition is necessary for yield prediction in practical projects. Shading/masking conditions result in the increase of PV cell stress, which degrades the electrical performance. The maximum displacement of the PV cell suffering hot-spot, up to 0.85 mm, is further beyond the compression range of ethylene vinyl acetate, causing structural damage to the PV module even not on fire.

Cognitive and Linguistic Contributions to Masked Speech Recognition in Children.

Purpose The goal of this study was to examine the effects of cognitive and linguistic skills on masked speech recognition for children with normal hearing in three different masking conditions: (a) speech-shaped noise (SSN), (b) amplitude-modulated SSN (AMSSN), and (c) two-talker speech (TTS). We hypothesized that children with better working memory and language skills would have better masked speech recognition than peers with poorer skills in these areas. Selective attention was predicted to affect performance in the TTS masker due to increased cognitive demands from informational masking. Method A group of 60 children in two age groups (5- to 6-year-olds and 9- to 10-year-olds) with normal hearing completed sentence recognition in SSN, AMSSN, and TTS masker conditions. Speech recognition thresholds for 50% correct were measured. Children also completed standardized measures of language, memory, and executive function. Results Children's speech recognition was poorer in the TTS relative to the SSN and AMSSN maskers. Older children had lower speech recognition thresholds than younger children for all masker conditions. Greater language abilities were associated with better sentence recognition for the younger children in all masker conditions, but there was no effect of language for older children. Better working memory and selective attention skills were associated with better masked sentence recognition for both age groups, but only in the TTS masker condition. Conclusions The decreasing influence of vocabulary on masked speech recognition for older children supports the idea that this relationship depends on an interaction between the language level of the stimuli and the listener's vocabulary. Increased cognitive demands associated with perceptually isolating the target talker and two competing masker talkers with a TTS masker may result in the recruitment of working memory and selective attention skills, effects that were not observed in SSN or AMSSN maskers. Future research should evaluate these effects across a broader range of stimuli or with children who have hearing loss.

Speech spoken by familiar people is more resistant to interference by linguistically similar speech.

Understanding speech in adverse conditions is affected by experience-a familiar voice is substantially more intelligible than an unfamiliar voice when competing speech is present, even if the content of the speech (the words) are controlled. This familiar-voice benefit is observed consistently, but its underpinnings are unclear: Do familiar voices simply attract more attention, are they inherently more intelligible because they have predictable acoustic characteristics, or are they more intelligible in a mixture because they are more resistant to interference from other sounds? We recruited pairs of native English-speaking participants who were friends or romantic couples. Participants reported words from closed-set English sentences (i.e., Oldenburg Matrix Test; Zokoll et al., 2013) spoken by a familiar talker (the participant's partner) or an unfamiliar talker. We compared 3 masker conditions that are acoustically similar but differ in their demands: (1) English Oldenburg sentences; (2) Oldenburg sentences in a language incomprehensible to the listener (Russian or Spanish); and (3) unintelligible signal-correlated noise. We adaptively varied the target-to-masker ratio to obtain 50% speech reception thresholds. We observed a large (∼5 dB) familiar-voice benefit when the target and masker were both English sentences. This benefit was attenuated (to ∼2 dB) when the masker was in an incomprehensible language and disappeared when it was signal-correlated noise. These results suggest that familiar voices did not benefit intelligibility because they were more predictable or because they attracted greater attention, rather familiarity with a target voice reduced interference from maskers that are linguistically similar to the target. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Tonal Language Speakers Are Better Able to Segregate Competing Speech According to Talker Sex Differences.

Purpose The aim of this study was to compare release from masking (RM) between Mandarin-speaking and English-speaking listeners with normal hearing for competing speech when target-masker sex cues, spatial cues, or both were available. Method Speech recognition thresholds (SRTs) for competing speech were measured in 21 Mandarin-speaking and 15 English-speaking adults with normal hearing using a modified coordinate response measure task. SRTs were measured for target sentences produced by a male talker in the presence of two masker talkers (different male talkers or female talkers). The target sentence was always presented directly in front of the listener, and the maskers were either colocated with the target or were spatially separated from the target (+90°, -90°). Stimuli were presented via headphones and were virtually spatialized using head-related transfer functions. Three masker conditions were used to measure RM relative to the baseline condition: (a) talker sex cues, (b) spatial cues, or (c) combined talker sex and spatial cues. Results The results showed large amounts of RM according to talker sex and/or spatial cues. There was no significant difference in SRTs between Chinese and English listeners for the baseline condition, where no talker sex or spatial cues were available. Furthermore, there was no significant difference in RM between Chinese and English listeners when spatial cues were available. However, RM was significantly larger for Chinese listeners when talker sex cues or combined talker sex and spatial cues were available. Conclusion Listeners who speak a tonal language such as Mandarin Chinese may be able to take greater advantage of talker sex cues than listeners who do not speak a tonal language.

Assessment of the difference limens for frequency, monosyllable articulation and word intelligibility by distantly-presented bone-conducted ultrasound.

Ultrasound can be clearly perceived by bone-conduction, and this "bone-conducted ultrasound (BCU)" can transmit speech information by using amplitude modulation (AM). Further, BCU can be perceived not only on the head but also on the distal parts of the body like the neck, trunk and arms. This "distantly-presented BCU" can be applied to the novel interface that can transmit sound information selectively to specific users who touches the vibrator. However, the ability to transmit sound information of distantly-presented BCU is unclear. First, to assess frequency discrimination ability, difference limens for frequency (DLFs) of the distantly-presented AM-BCU were measured with/without a low-pass masking noise that masked the self-demodulated components generated by the nonlinearity of biological tissues. DLFs comparable to that of air-conducted sounds were observed, whereas DLFs significantly increased above 1 kHz under the masking condition. These results suggest that practical frequency discrimination ability can be obtained even when BCUs were presented to distal body parts. Additionally, it is indicated that the demodulated components may contribute to transmitting frequency information above 1 kHz. Second, monosyllable articulation and word intelligibility tests were conducted in Japanese. The intelligibility and articulation at the neck were 55% and 38% respectively, whereas they decreased as the stimulus placement gets farther from the head. The results suggest the distantly-presented BCU device can be applied to transmission of speech information.

Player–surface interactions: perception in elite soccer and rugby players on artificial and natural turf

ABSTRACTArtificial turf (AT) is common at all levels of soccer and rugby. Employing an interdisciplinary design, this study aimed to examine the extent to which the negative attitude commonly expressed by players concerning AT is based on the difference in technique between AT and natural turf (NT), or due to pre-existing biases. Thirty professional soccer and rugby players performed a defined set of movements with masked and normal perception conditions on NT and AT. Two-dimensional kinematic analysis (100 Hz) of characteristics in parallel to a psychological assessment of the impact of cognitive bias for a playing surface was assessed. No significant interaction effects between the level of perception and surface type were found. For AT, contact time (CT) was shorter across conditions, while for NT rugby players had longer CT during acceleration/deceleration phases and shorter flight times. Pre-existing negative bias against AT was found during the normal perception trials in the technology acceptance model (Usefulness and Ease of Use) and the general preference questions on how much the athlete would like to play a game on it. The results suggest that opinion was not driven by surface characteristics, but by a cognitive bias, players brought with them to the pitch.