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Broadband data were effectively classified to species while simulated multi-frequency narrowband data were categorized at rates near chance, supporting the presumption that greater bandwidth increases the information available for the characterization and classification of biological targets.This study examined acoustic characteristics of vowels produced by speakers from Louisiana, one of the states in the Southern English dialect region. First, how Louisiana vowels differ from or are similar to the reported patterns of Southern dialect were examined. Then, within-dialect differences across regions in Louisiana were examined. Thirty-four female adult monolingual speakers of American English from Louisiana, ranging in age from 18 to 23, produced English monosyllabic words containing 11 vowels /i, ɪ, e, ɛ, æ, ʌ, u, ʊ, o, ɔ, ɑ/. The first two formant frequencies at the midpoint of the vowel nucleus, direction, and amount of formant changes across three different time points (20, 50, and 80%), and vowel duration were compared to previously reported data on Southern vowels. Overall, Louisiana vowels showed patterns consistent with previously reported characteristics of Southern vowels that reflect ongoing changes in the Southern dialect (no evidence of acoustic reversal of tense-lax pairs, more specifically no peripheralization of front vowels). Some dialect-specific patterns were also observed (a relatively lesser degree of formant changes and slightly shorter vowel duration). These patterns were consistent across different regions within Louisiana.An acoustic beamforming concept is presented that alleviates some misrepresentation caused by deconvolution algorithms that can oversimplify distributed sources as a series of point sources. In the Array Pairing Method (APM) an initial array beamforms the acoustic source, then an iterative randomized array is calculated whereby the square-rooted product of the beamformer output possesses a minimum product of Maximum Sidelobe Level (MSL) and Main Lobe Width (MLW). A single and distributed source simulation and a single and dual speaker experiment using the APM reveal significant improvements in MSL and MLW and resolution in the distributed source region.New Orleans English (NOE) has always stood out amongst Southern Englishes, since NOE speakers do not participate in the Southern vowel shift, and instead display features more commonly associated with New York City English. While these traditional features of NOE are on the decline, this study establishes the adoption of a new feature in the dialect that is similarly distinctive within the Gulf South the pre-voiceless raising of the nucleus of /au/. Based on statistical analyses and consideration of the social context in post-Katrina New Orleans, this paper argues that this feature is a change in progress which appears to pre-date the demographic shifts following Hurricane Katrina, and which arose independently rather than due to contact with /au/-raising speakers. The social and phonetic findings in this paper converge to support arguments for the naturalness of raising in pre-voiceless environments, and for the likelihood of this feature being more widely adopted within the region. Moreover, the presence of Canadian raising of /au/ in NOE represents an additional way that the local dialect continues to diverge from patterns in the vowel systems found in nearby Southern dialects, and retain its uniqueness within the American South.Voiced stops tend to be preceded by longer vowels and produced with a more advanced tongue root than voiceless stops. The duration of a vowel is affected by the voicing of the stop that follows, and in many languages vowels are longer when followed by voiced stops. Tongue root advancement is known to be an articulatory mechanism, which ensures the right pressure conditions for the maintenance of voicing during closure as dictated by the aerodynamic voicing constraint. In this paper, it is argued that vowel duration and tongue root advancement have a direct statistical relationship. Drawing from acoustic and ultrasound tongue imaging data from 17 speakers of Italian and Polish in total, it is proposed that the comparatively later closure onset of voiced stops is responsible for both greater root advancement and shorter closure durations of voiced stops. It is further shown that tongue root advancement is initiated during the vowel, and vowel duration and tongue root position at vowel offset are positively correlated so that longer vowel durations correspond to greater tongue root advancement.The perception of spectrotemporal changes is crucial for distinguishing between acoustic signals, including vocalizations. Temporal modulation transfer functions (TMTFs) have been measured in many species and reveal that the discrimination of amplitude modulation suffers at rapid modulation frequencies. TMTFs were measured in six CBA/CaJ mice in an operant conditioning procedure, where mice were trained to discriminate an 800 ms amplitude modulated white noise target from a continuous noise background. TMTFs of mice show a bandpass characteristic, with an upper limit cutoff frequency of around 567 Hz. Within the measured modulation frequencies ranging from 5 Hz to 1280 Hz, the mice show a best sensitivity for amplitude modulation at around 160 Hz. learn more To look for a possible parallel evolution between sound perception and production in living organisms, we also analyzed the components of amplitude modulations embedded in natural ultrasonic vocalizations (USVs) emitted by this strain. We found that the cutoff frequency of amplitude modulation in most of the individual USVs is around their most sensitive range obtained from the psychoacoustic experiments. Further analyses of the duration and modulation frequency ranges of USVs indicated that the broader the frequency ranges of amplitude modulation in natural USVs, the shorter the durations of the USVs.Acoustic feedback in hearing aids occurs due to the coupling between the hearing aid loudspeaker and microphones. In order to reduce acoustic feedback, adaptive filters are often used to estimate the feedback path. To increase the convergence speed and decrease the computational complexity of the adaptive algorithms, it has been proposed to split the acoustic feedback path into a time-invariant fixed part and a time-varying variable part. A key question of this approach is how to determine the fixed part. In this paper, two approaches are investigated (1) a digital filter design approach that makes use of the signals of at least two hearing aid microphones and (2) a defined physical location approach using an electro-acoustic model and the signals of one hearing aid microphone and an additional ear canal microphone. An experimental comparison using measured acoustic feedback paths showed that both approaches enable one to reduce the number of variable part coefficients. It is shown that individualization of the fixed part increases the performance.

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