The aims of this research were (1) to provide a description of spurfowl Pternistis spp. calls and their social context;(2) to describe the divergence of advertisement calls;and (3) to appropri-ate 23 spurfowl species ...The aims of this research were (1) to provide a description of spurfowl Pternistis spp. calls and their social context;(2) to describe the divergence of advertisement calls;and (3) to appropri-ate 23 spurfowl species to homologous sound groups which have been synthesized with recognized monophyletic groups within Pternistis spurfowls. Sound group partitioning was primarily based on male advertisement calls. A total of 218 recordings (rendering^300 identifiable calls) were analyzed covering 22 out of 23 spurfowl species in Africa. One species was assessed from written accounts. The repertoire size per spurfowl varies between 7 and 11 calls. Spurfowl calls were arranged into three broad categories including (1) advertisement calls;(2) maintenance calls including distress calls, juve-nile whining (“mews”), cheeps and comfort calls;and (3) male-female and female-offspring bonding calls. Spurfowl species were set out in eight sound groups of which five were more or less congruent with the monophyletic groups of Hall (1963), but sound groups produced more partitioning as Hall described only five groups relevant to Pternistis spp. The divergence of advertisement calls appar-ently minimizes hybridization between sympatric species but the“genetic distance”between spurfowl species is relatively small causing hybridization among spurfowl species. Despite the vocalizations of Hartlaub’s Spurfowl (P. hartlaubi) differing significantly from the rest of the spurfowls, sound analy-ses suggest that it remains within Pternistis.展开更多
An improved speech absence probability estimation was proposed using environmental noise classification for speech enhancement.A relevant noise estimation approach,known as the speech presence uncertainty tracking met...An improved speech absence probability estimation was proposed using environmental noise classification for speech enhancement.A relevant noise estimation approach,known as the speech presence uncertainty tracking method,requires seeking the "a priori" probability of speech absence that is derived by applying microphone input signal and the noise signal based on the estimated value of the "a posteriori" signal-to-noise ratio(SNR).To overcome this problem,first,the optimal values in terms of the perceived speech quality of a variety of noise types are derived.Second,the estimated optimal values are assigned according to the determined noise type which is classified by a real-time noise classification algorithm based on the Gaussian mixture model(GMM).The proposed algorithm estimates the speech absence probability using a noise classification algorithm which is based on GMM to apply the optimal parameter of each noise type,unlike the conventional approach which uses a fixed threshold and smoothing parameter.The performance of the proposed method was evaluated by objective tests,such as the perceptual evaluation of speech quality(PESQ) and composite measure.Performance was then evaluated by a subjective test,namely,mean opinion scores(MOS) under various noise environments.The proposed method show better results than existing methods.展开更多
Valeo, involved in engine cooling fan system design for many years, is interested in noise prediction tools for axial fans. Thus, this paper describes a two-part study of tonal noise computation. The first part deals ...Valeo, involved in engine cooling fan system design for many years, is interested in noise prediction tools for axial fans. Thus, this paper describes a two-part study of tonal noise computation. The first part deals with the prediction of tonal noise using analytical models. As for the second part, it describes a hybrid approach for predicting tonal noise where the sources are extracted from an Unsteady Reynolds-Averaged Naviers-Stocks （URANS） simulation and then propagated into the far, free field using the Ffowcs Williams and Hawkings＇ acoustic analogy. The computational domain is meshed with 46 million polyhedral elements and the simulation takes into account the exact geometry of the rotor blades, the stator blades and the shroud. The results from the first part show that analytical models can be used for comparisons between different fan geometries, but are unable to provide accurate noise predictions compared to experimental results. The simulation shows non-periodic blade loading over a whole fan revolution, and different blade loading between the blades. This introduces some bias in the assessment of the acoustic performance of the fan. Overall, the results from the hybrid method are in accordance with the experimental results.展开更多
Vocal individuality is widespread in social animals. Individual variation in vocalizations is a prereq- uisite for discriminating among conspecifics and may have facilitated the evolution of large complex societies. R...Vocal individuality is widespread in social animals. Individual variation in vocalizations is a prereq- uisite for discriminating among conspecifics and may have facilitated the evolution of large complex societies. Ring-tailed lemurs Lemur catta live in relatively large social groups, have con- spicuous vocal repertoires, and their species-specific utterances can be interpreted in light of source-filter theory of vocal production. Indeed, their utterances allow individual discrimination and even recognition thanks to the resonance frequencies of the vocal tract. The purpose of this study is to determine which distinctive vocal features can be derived from the morphology of the upper vocal tract. To accomplish this, we built computational models derived from anatomical measurements collected on lemur cadavers and compared the results with the spectrographic out- put of vocalizations recorded from ex situ live individuals. Our results demonstrate that the mor- phological variation of the ring-tailed lemur vocal tract explains individual distinctiveness of their species-specific utterances. We also provide further evidence that vocal tract modeling is a power- ful tool for studying the vocal output of non-human primates.展开更多
文摘The aims of this research were (1) to provide a description of spurfowl Pternistis spp. calls and their social context;(2) to describe the divergence of advertisement calls;and (3) to appropri-ate 23 spurfowl species to homologous sound groups which have been synthesized with recognized monophyletic groups within Pternistis spurfowls. Sound group partitioning was primarily based on male advertisement calls. A total of 218 recordings (rendering^300 identifiable calls) were analyzed covering 22 out of 23 spurfowl species in Africa. One species was assessed from written accounts. The repertoire size per spurfowl varies between 7 and 11 calls. Spurfowl calls were arranged into three broad categories including (1) advertisement calls;(2) maintenance calls including distress calls, juve-nile whining (“mews”), cheeps and comfort calls;and (3) male-female and female-offspring bonding calls. Spurfowl species were set out in eight sound groups of which five were more or less congruent with the monophyletic groups of Hall (1963), but sound groups produced more partitioning as Hall described only five groups relevant to Pternistis spp. The divergence of advertisement calls appar-ently minimizes hybridization between sympatric species but the“genetic distance”between spurfowl species is relatively small causing hybridization among spurfowl species. Despite the vocalizations of Hartlaub’s Spurfowl (P. hartlaubi) differing significantly from the rest of the spurfowls, sound analy-ses suggest that it remains within Pternistis.
基金Project supported by an Inha University Research GrantProject(10031764) supported by the Strategic Technology Development Program of Ministry of Knowledge Economy,Korea
文摘An improved speech absence probability estimation was proposed using environmental noise classification for speech enhancement.A relevant noise estimation approach,known as the speech presence uncertainty tracking method,requires seeking the "a priori" probability of speech absence that is derived by applying microphone input signal and the noise signal based on the estimated value of the "a posteriori" signal-to-noise ratio(SNR).To overcome this problem,first,the optimal values in terms of the perceived speech quality of a variety of noise types are derived.Second,the estimated optimal values are assigned according to the determined noise type which is classified by a real-time noise classification algorithm based on the Gaussian mixture model(GMM).The proposed algorithm estimates the speech absence probability using a noise classification algorithm which is based on GMM to apply the optimal parameter of each noise type,unlike the conventional approach which uses a fixed threshold and smoothing parameter.The performance of the proposed method was evaluated by objective tests,such as the perceptual evaluation of speech quality(PESQ) and composite measure.Performance was then evaluated by a subjective test,namely,mean opinion scores(MOS) under various noise environments.The proposed method show better results than existing methods.
文摘Valeo, involved in engine cooling fan system design for many years, is interested in noise prediction tools for axial fans. Thus, this paper describes a two-part study of tonal noise computation. The first part deals with the prediction of tonal noise using analytical models. As for the second part, it describes a hybrid approach for predicting tonal noise where the sources are extracted from an Unsteady Reynolds-Averaged Naviers-Stocks （URANS） simulation and then propagated into the far, free field using the Ffowcs Williams and Hawkings＇ acoustic analogy. The computational domain is meshed with 46 million polyhedral elements and the simulation takes into account the exact geometry of the rotor blades, the stator blades and the shroud. The results from the first part show that analytical models can be used for comparisons between different fan geometries, but are unable to provide accurate noise predictions compared to experimental results. The simulation shows non-periodic blade loading over a whole fan revolution, and different blade loading between the blades. This introduces some bias in the assessment of the acoustic performance of the fan. Overall, the results from the hybrid method are in accordance with the experimental results.
文摘Vocal individuality is widespread in social animals. Individual variation in vocalizations is a prereq- uisite for discriminating among conspecifics and may have facilitated the evolution of large complex societies. Ring-tailed lemurs Lemur catta live in relatively large social groups, have con- spicuous vocal repertoires, and their species-specific utterances can be interpreted in light of source-filter theory of vocal production. Indeed, their utterances allow individual discrimination and even recognition thanks to the resonance frequencies of the vocal tract. The purpose of this study is to determine which distinctive vocal features can be derived from the morphology of the upper vocal tract. To accomplish this, we built computational models derived from anatomical measurements collected on lemur cadavers and compared the results with the spectrographic out- put of vocalizations recorded from ex situ live individuals. Our results demonstrate that the mor- phological variation of the ring-tailed lemur vocal tract explains individual distinctiveness of their species-specific utterances. We also provide further evidence that vocal tract modeling is a power- ful tool for studying the vocal output of non-human primates.
