The use of acoustic cues in phonetic perception: Effects of spectral degradation, limited bandwidth and background noise

Hearing impairment, cochlear implantation, background noise and other auditory degradations result in the loss or distortion of sound information thought to be critical to speech perception. In many cases, listeners can still identify speech sounds despite degradations, but understanding of how this is accomplished is incomplete. Experiments presented here tested the hypothesis that listeners would utilize acoustic-phonetic cues differently if one or more cues were degraded by hearing impairment or simulated hearing impairment. Results supported this hypothesis for various listening conditions that are directly relevant for clinical populations. Analysis included mixed-effects logistic modeling of contributions of individual acoustic cues for various contrasts. Listeners with cochlear implants (CIs) or normal-hearing (NH) listeners in CI simulations showed increased use of acoustic cues in the temporal domain and decreased use of cues in the spectral domain for the tense/lax vowel contrast and the word-final fricative voicing contrast. For the word-initial stop voicing contrast, NH listeners made less use of voice-onset time and greater use of voice pitch in conditions that simulated high-frequency hearing impairment and/or masking noise; influence of these cues was further modulated by consonant place of articulation. A pair of experiments measured phonetic context effects for the "s/sh" contrast, replicating previously observed effects for NH listeners and generalizing them to CI listeners as well, despite known deficiencies in spectral resolution for CI listeners. For NH listeners in CI simulations, these context effects were absent or negligible. Audio-visual delivery of this experiment revealed enhanced influence of visual lip-rounding cues for CI listeners and NH listeners in CI simulations. Additionally, CI listeners demonstrated that visual cues to gender influence phonetic perception in a manner consistent with gender-related voice acoustics. All of these results suggest that listeners are able to accommodate challenging listening situations by capitalizing on the natural (multimodal) covariance in speech signals. Additionally, these results imply that there are potential differences in speech perception by NH listeners and listeners with hearing impairment that would be overlooked by traditional word recognition or consonant confusion matrix analysis

The sound of meaning: theories of voice in twentieth-century thought and performance

This dissertation addresses the problem of the denigration of the voice in poststructural theory and contemporary performance criticism. The problem has antecedents in twentieth-century language philosophy. Saussure defines language as a compendium of arbitrary words recognized according to the degrees of phonetic difference between them. Since for Saussure the arbitrary words of language also designate arbitrary concepts, he concludes that the sounds of words cannot be thought constituent of their sense. After Saussure, structuralism dislodges the voice from its privileged position in the phonologic discourses of Western thought. Poststructuralism views meaning as a product of socially constructed language systems, and it argues that neither the voice nor the speaking subject can be afforded linguistic agency. A strain of contemporary theatre criticism, premised upon poststructuralism, interprets the postmodern stage as a site in which the voice, language, and the speaking subject come under critique and suspicion, stripped of agency and communicative efficacy. This dissertation investigates twentieth-century theories of voice, language, and speech in order to define the status of the voice in various disciplines ranging from paleoanthropology, phenomenology, structuralism, speech act theory, theatre semiotics, the philosophies of technology, and media studies. By comparing the status of the voice in other disciplines, this dissertation argues for a recuperation of the voice against the denigration evident in poststructural theory and performance criticism. Relying on Heidegger\u27s phenomenal view of language, the autonomy of the voice in speech act theory and theatre semiotics, the centrality of vocalized language in human evolution, and the resurgence of orality in electronic media, this dissertation argues that the voice continues to act as an important and primary signifying agent on the postmodern stage, regardless of poststructural arguments to the contrary

Auf einem menschlichen Gehörmodell basierende Elektrodenstimulationsstrategie für Cochleaimplantate

Cochleaimplantate (CI), verbunden mit einer professionellen Rehabilitation, haben mehreren hunderttausenden Hörgeschädigten die verbale Kommunikation wieder ermöglicht. Betrachtet man jedoch die Rehabilitationserfolge, so haben CI-Systeme inzwischen ihre Grenzen erreicht. Die Tatsache, dass die meisten CI-Träger nicht in der Lage sind, Musik zu genießen oder einer Konversation in geräuschvoller Umgebung zu folgen, zeigt, dass es noch Raum für Verbesserungen gibt.Diese Dissertation stellt die neue CI-Signalverarbeitungsstrategie Stimulation based on Auditory Modeling (SAM) vor, die vollständig auf einem Computermodell des menschlichen peripheren Hörsystems beruht.Im Rahmen der vorliegenden Arbeit wurde die SAM Strategie dreifach evaluiert: mit vereinfachten Wahrnehmungsmodellen von CI-Nutzern, mit fünf CI-Nutzern, und mit 27 Normalhörenden mittels eines akustischen Modells der CI-Wahrnehmung. Die Evaluationsergebnisse wurden stets mit Ergebnissen, die durch die Verwendung der Advanced Combination Encoder (ACE) Strategie ermittelt wurden, verglichen. ACE stellt die zurzeit verbreitetste Strategie dar. Erste Simulationen zeigten, dass die Sprachverständlichkeit mit SAM genauso gut wie mit ACE ist. Weiterhin lieferte SAM genauere binaurale Merkmale, was potentiell zu einer Verbesserung der Schallquellenlokalisierungfähigkeit führen kann. Die Simulationen zeigten ebenfalls einen erhöhten Anteil an zeitlichen Pitchinformationen, welche von SAM bereitgestellt wurden. Die Ergebnisse der nachfolgenden Pilotstudie mit fünf CI-Nutzern zeigten mehrere Vorteile von SAM auf. Erstens war eine signifikante Verbesserung der Tonhöhenunterscheidung bei Sinustönen und gesungenen Vokalen zu erkennen. Zweitens bestätigten CI-Nutzer, die kontralateral mit einem Hörgerät versorgt waren, eine natürlicheren Klangeindruck. Als ein sehr bedeutender Vorteil stellte sich drittens heraus, dass sich alle Testpersonen in sehr kurzer Zeit (ca. 10 bis 30 Minuten) an SAM gewöhnen konnten. Dies ist besonders wichtig, da typischerweise Wochen oder Monate nötig sind. Tests mit Normalhörenden lieferten weitere Nachweise für die verbesserte Tonhöhenunterscheidung mit SAM.Obwohl SAM noch keine marktreife Alternative ist, versucht sie den Weg für zukünftige Strategien, die auf Gehörmodellen beruhen, zu ebnen und ist somit ein erfolgversprechender Kandidat für weitere Forschungsarbeiten.Cochlear implants (CIs) combined with professional rehabilitation have enabled several hundreds of thousands of hearing-impaired individuals to re-enter the world of verbal communication. Though very successful, current CI systems seem to have reached their peak potential. The fact that most recipients claim not to enjoy listening to music and are not capable of carrying on a conversation in noisy or reverberative environments shows that there is still room for improvement.This dissertation presents a new cochlear implant signal processing strategy called Stimulation based on Auditory Modeling (SAM), which is completely based on a computational model of the human peripheral auditory system.SAM has been evaluated through simplified models of CI listeners, with five cochlear implant users, and with 27 normal-hearing subjects using an acoustic model of CI perception. Results have always been compared to those acquired using Advanced Combination Encoder (ACE), which is today’s most prevalent CI strategy. First simulations showed that speech intelligibility of CI users fitted with SAM should be just as good as that of CI listeners fitted with ACE. Furthermore, it has been shown that SAM provides more accurate binaural cues, which can potentially enhance the sound source localization ability of bilaterally fitted implantees. Simulations have also revealed an increased amount of temporal pitch information provided by SAM. The subsequent pilot study, which ran smoothly, revealed several benefits of using SAM. First, there was a significant improvement in pitch discrimination of pure tones and sung vowels. Second, CI users fitted with a contralateral hearing aid reported a more natural sound of both speech and music. Third, all subjects were accustomed to SAM in a very short period of time (in the order of 10 to 30 minutes), which is particularly important given that a successful CI strategy change typically takes weeks to months. An additional test with 27 normal-hearing listeners using an acoustic model of CI perception delivered further evidence for improved pitch discrimination ability with SAM as compared to ACE.Although SAM is not yet a market-ready alternative, it strives to pave the way for future strategies based on auditory models and it is a promising candidate for further research and investigation

Listening in a second language: a pupillometric investigation of the effect of semantic and acoustic cues on listening effort

Non-native listeners live a great part of their day immersed in a second language environment. Challenges arise because many linguistic interactions happen in noisy environments, and because their linguistic knowledge is imperfect. Pupillometry was shown to provide a reliable measure of cognitive effort during listening. This research aims to investigate by means of pupillometry how listening effort is modulated by the intelligibility level of the listening task, the availability of contextual and acoustic cues and by the language background of listeners (native vs non-native). In Study 1, listening effort in native and non-native listeners was evaluated during a sentence perception task in noise across different intelligibility levels. Results indicated that listening effort was increased for non-native compared to native listeners, when the intelligibility levels were equated across the two groups. In Study 2, using a similar method, materials included predictable and semantically anomalous sentences, presented in a plain and a clear speaking style. Results confirmed an increased listening effort for non-native compared to native listeners. Listening effort was overall reduced when participants attended to clear speech. Moreover, effort reduction after the sentence ended was delayed for less proficient non-native listeners. In Study 3, the contribution of semantic content spanning over several sentences was evaluated using lists of semantically related and unrelated stimuli. The presence of semantic cues across sentences led to a reduction in listening effort for native listeners as reflected by the peak pupil dilation, while non-native listeners did not show the same benefit. In summary, this research consistently showed an increased listening effort for non-native compared to native listeners, at equated levels of intelligibility. Additionally, the use of a clear speaking style proved to be an effective strategy to enhance comprehension and to reduce cognitive effort in native and non-native listeners

Communications, Strategies & Performance

Communications, Strategies & Performance is a compilation of open educational resources that provides an in-depth analysis on topics ranging from public speaking to the communication process to the ethics and cultural considerations of speech and communication. Course: COM 202https://spiral.lynn.edu/ludp/1040/thumbnail.jp

Using HeidiSongs Music as an Instructional Tool in the Elementary School Classroom: A Case Study

The purpose of this qualitative multiple case study is to understand how teachers use HeidiSongs music as an instructional tool in the elementary school classroom. HeidiSongs uses multisensory structured language education to teach by engaging multiple senses simultaneously to increase retention. The theories guiding this study include Gardner’s theory of multiple intelligences, which involves kinesthetic intelligences among other types of intelligences, and Krashen’s theory of second language acquisition. HeidiSongs uses both musical and kinesthetic activities to enhance literacy. The central research question focused on how teachers use HeidiSongs music as an instructional tool in the elementary school classroom. The sub-questions explored the different instructional settings where this literacy instruction could take place: whole group, small group, and individual instruction. Eleven participants were current or former users of HeidiSongs music, and data was collected virtually through documentation, individual interviews, and a single focus group interview. Data was analyzed through cross-case synthesis, searching for patterns, forming naturalistic generalizations, and explanation building. Findings indicated HeidiSongs is most applicable in the whole group setting in the elementary school classroom, with teachers and students using recall of the songs in small group and individual worktime to enhance memory. Teachers enjoyed the combination of multisensory music and movement in HeidiSongs and reported an overall positive effect on student engagement, even in diverse populations. Further research on instructional data distinguishing between audio, visual, or animated versions of the songs could help teachers determine which version of the songs is most ideal for each classroom