Silent-speech enhancement using body-conducted vocal-tract resonance signals

The physical characteristics of weak body-conducted vocal-tract resonance signals called non-audible murmur (NAM) and the acoustic characteristics of three sensors developed for detecting these signals have been investigated. NAM signals attenuate 50 dB at 1 kHz; this attenuation consists of 30-dB full-range attenuation due to air-to-body transmission loss and 10 dB/octave spectral decay due to a sound propagation loss within the body. These characteristics agree with the spectral characteristics of measured NAM signals. The sensors have a sensitivity of between 41 and 58 dB [V/Pa] at I kHz, and the mean signal-to-noise ratio of the detected signals was 15 dB. On the basis of these investigations, three types of silent-speech enhancement systems were developed: (1) simple, direct amplification of weak vocal-tract resonance signals using a wired urethane-elastomer NAM microphone, (2) simple, direct amplification using a wireless urethane-elastomer-duplex NAM microphone, and (3) transformation of the weak vocal-tract resonance signals sensed by a soft-silicone NAM microphone into whispered speech using statistical conversion. Field testing of the systems showed that they enable voice impaired people to communicate verbally using body-conducted vocal-tract resonance signals. Listening tests demonstrated that weak body-conducted vocal-tract resonance sounds can be transformed into intelligible whispered speech sounds. Using these systems, people with voice impairments can re-acquire speech communication with less effort. (C) 2009 Elsevier B.V. All rights reserved.ArticleSPEECH COMMUNICATION. 52(4):301-313 (2010)journal articl

MOA-2020-BLG-135Lb: A New Neptune-class Planet for the Extended MOA-II Exoplanet Microlens Statistical Analysis

We report the light-curve analysis for the event MOA-2020-BLG-135, which leads to the discovery of a new Neptune-class planet, MOA-2020-BLG-135Lb. With a derived mass ratio of $q=1.52_{-0.31}^{+0.39} \times 10^{-4}$ and separation $s\approx1$, the planet lies exactly at the break and likely peak of the exoplanet mass-ratio function derived by the MOA collaboration (Suzuki et al. 2016). We estimate the properties of the lens system based on a Galactic model and considering two different Bayesian priors: one assuming that all stars have an equal planet-hosting probability and the other that planets are more likely to orbit more massive stars. With a uniform host mass prior, we predict that the lens system is likely to be a planet of mass $m_\mathrm{planet}=11.3_{-6.9}^{+19.2} M_\oplus$ and a host star of mass $M_\mathrm{host}=0.23_{-0.14}^{+0.39} M_\odot$, located at a distance $D_L=7.9_{-1.0}^{+1.0}\;\mathrm{kpc}$. With a prior that holds that planet occurrence scales in proportion to the host star mass, the estimated lens system properties are $m_\mathrm{planet}=25_{-15}^{+22} M_\oplus$, $M_\mathrm{host}=0.53_{-0.32}^{+0.42} M_\odot$, and $D_L=8.3_{-1.0}^{+0.9}\; \mathrm{kpc}$. This planet qualifies for inclusion in the extended MOA-II exoplanet microlens sample.Comment: 22 pages, 6 figures, 4 tables, submitted to the AAS Journal

KMT-2021-BLG-1077L: The fifth confirmed multiplanetary system detected by microlensing

The high-magnification microlensing event KMT-2021-BLG-1077 exhibits a subtle and complex anomaly pattern in the region around the peak. We analyze the lensing light curve of the event with the aim of revealing the nature of the anomaly. We test various models in combination with several interpretations. We find that the anomaly cannot be explained by the usual three-body (2L1S and 1L2S) models. The 2L2S model improves the fit compared to the three-body models, but it still leaves noticeable residuals. On the other hand, the 3L1S interpretation yields a model explaining all the major anomalous features in the lensing light curve. According to the 3L1S interpretation, the estimated mass ratios of the lens companions to the primary are $\sim 1.56 \times 10^{-3}$ and $\sim 1.75 \times 10^{-3}$, which correspond to $\sim 1.6$ and $\sim 1.8$ times the Jupiter/Sun mass ratio, respectively, and therefore the lens is a multiplanetary system containing two giant planets. With the constraints of the event time-scale and angular Einstein radius, it is found that the host of the lens system is a low-mass star of mid-to-late M spectral type with a mass of $M_{\rm h} = 0.14^{+0.19}_{-0.07}~M_\odot$, and it hosts two gas giant planets with masses of $M_{\rm p_1}=0.22^{+0.31}_{-0.12}~M_{\rm J}$ and $M_{\rm p_2}=0.25^{+0.35}_{-0.13}~M_{\rm J}$. The planets lie beyond the snow line of the host with projected separations of $a_{\perp, {\rm p}_1}=1.26^{+1.41}_{-1.08}~{\rm AU}$ and $a_{\perp, {\rm p}_2}=0.93^{+1.05}_{-0.80}~{\rm AU}$. The planetary system resides in the Galactic bulge at a distance of $D_{\rm L}=8.24^{+1.02}_{-1.16}~{\rm kpc}$. The lens of the event is the fifth confirmed multiplanetary system detected by microlensing following OGLE-2006-BLG-109L, OGLE-2012-BLG-0026L, OGLE-2018-BLG-1011L, and OGLE-2019-BLG-0468L.Comment: 9 pages, 8 figure

KMT-2021-BLG-1150Lb: Microlensing planet detected through a densely covered planetary-caustic signal

Recently, there have been reports of various types of degeneracies in the interpretation of planetary signals induced by planetary caustics. In this work, we check whether such degeneracies persist in the case of well-covered signals by analyzing the lensing event KMT-2021-BLG-1150, for which the light curve exhibits a densely and continuously covered short-term anomaly. In order to identify degenerate solutions, we thoroughly investigate the parameter space by conducting dense grid searches for the lensing parameters. We then check the severity of the degeneracy among the identified solutions. We identify a pair of planetary solutions resulting from the well-known inner-outer degeneracy, and find that interpreting the anomaly is not subject to any degeneracy other than the inner-outer degeneracy. The measured parameters of the planet separation (normalized to the Einstein radius) and mass ratio between the lens components are $(s, q)_{\rm in}\sim (1.297, 1.10\times 10^{-3})$ for the inner solution and $(s, q)_{\rm out}\sim (1.242, 1.15\times 10^{-3})$ for the outer solution. According to a Bayesian estimation, the lens is a planetary system consisting of a planet with a mass $M_{\rm p}=0.88^{+0.38}_{-0.36}~M_{\rm J}$ and its host with a mass $M_{\rm h}=0.73^{+0.32}_{-0.30}~M_\odot$ lying toward the Galactic center at a distance $D_{\rm L} =3.8^{+1.3}_{-1.2}$~kpc. By conducting analyses using mock data sets prepared to mimic those obtained with data gaps and under various observational cadences, it is found that gaps in data can result in various degenerate solutions, while the observational cadence does not pose a serious degeneracy problem as long as the anomaly feature can be delineated.Comment: 9 pages, 8 figure

Mass Production of 2021 KMTNet Microlensing Planets III: Analysis of Three Giant Planets

We present the analysis of three more planets from the KMTNet 2021 microlensing season. KMT-2021-BLG-0119Lb is a $\sim 6\, M_{\rm Jup}$ planet orbiting an early M-dwarf or a K-dwarf, KMT-2021-BLG-0192Lb is a $\sim 2\, M_{\rm Nep}$ planet orbiting an M-dwarf, and KMT-2021-BLG-0192Lb is a $\sim 1.25\, M_{\rm Nep}$ planet orbiting a very--low-mass M dwarf or a brown dwarf. These by-eye planet detections provide an important comparison sample to the sample selected with the AnomalyFinder algorithm, and in particular, KMT-2021-BLG-2294, is a case of a planet detected by-eye but not by-algorithm. KMT-2021-BLG-2294Lb is part of a population of microlensing planets around very-low-mass host stars that spans the full range of planet masses, in contrast to the planet population at $\lesssim 0.1\,$ au, which shows a strong preference for small planets.Comment: 17 pages, 12 figures, 7 tables. Accept for publication in The Astronomical Journa

KMT-2022-BLG-0440Lb: A New q<10−4q < 10^{-4} Microlensing Planet with the Central-Resonant Caustic Degeneracy Broken

We present the observations and analysis of a high-magnification microlensing planetary event, KMT-2022-BLG-0440, for which the weak and short-lived planetary signal was covered by both the KMTNet survey and follow-up observations. The binary-lens models with a central caustic provide the best fits, with a planet/host mass ratio, $q = 0.75$--$1.00 \times 10^{-4}$ at $1\sigma$. The binary-lens models with a resonant caustic and a brown-dwarf mass ratio are both excluded by $\Delta\chi^2 > 70$. The binary-source model can fit the anomaly well but is rejected by the ``color argument'' on the second source. From Bayesian analyses, it is estimated that the host star is likely a K or M dwarf located in the Galactic disk, the planet probably has a Neptune-mass, and the projected planet-host separation is $1.9^{+0.6}_{-0.7}$ or $4.6^{+1.4}_{-1.7}$ au, subject to the close/wide degeneracy. This is the third $q < 10^{-4}$ planet from a high-magnification planetary signal ($A \gtrsim 65$). Together with another such planet, KMT-2021-BLG-0171Lb, the ongoing follow-up program for the KMTNet high-magnification events has demonstrated its ability in detecting high-magnification planetary signals for $q < 10^{-4}$ planets, which are challenging for the current microlensing surveys.Comment: MNRAS accepte

Systematic KMTNet Planetary Anomaly Search. V. Complete Sample of 2018 Prime-Field

We complete the analysis of all 2018 prime-field microlensing planets identified by the KMTNet AnomalyFinder. Among the 10 previously unpublished events with clear planetary solutions, 8 are either unambiguously planetary or are very likely to be planetary in nature: OGLE-2018-BLG-1126, KMT-2018-BLG-2004, OGLE-2018-BLG-1647, OGLE-2018-BLG-1367, OGLE-2018-BLG-1544, OGLE-2018-BLG-0932, OGLE-2018-BLG-1212, and KMT-2018-BLG-2718. Combined with the 4 previously published new AnomalyFinder events and 12 previously published (or in preparation) planets that were discovered by eye, thismakes a total of 24 2018 prime-field planets discovered or recovered by AnomalyFinder. Together with a paper in preparation on 2018 sub-prime planets, this work lays the basis for the first statistical analysis of the planet mass-ratio function based on planets identified in KMTNet data. By systematically applying the heuristic analysis of Hwang et al. (2022) to each event, we identify the small modification in their formalism that is needed to unify the so-called close/wide and inner/outer degeneracies, as conjectured byComment: 22 pages, 14 tables, 15 figure

KMT-2023-BLG-1431Lb: A New q<10−4q < 10^{-4} Microlensing Planet from a Subtle Signature

The current studies of microlensing planets are limited by small number statistics. Follow-up observations of high-magnification microlensing events can efficiently form a statistical planetary sample. Since 2020, the Korea Microlensing Telescope Network (KMTNet) and the Las Cumbres Observatory (LCO) global network have been conducting a follow-up program for high-magnification KMTNet events. Here, we report the detection and analysis of a microlensing planetary event, KMT-2023-BLG-1431, for which the subtle (0.05 magnitude) and short-lived (5 hours) planetary signature was characterized by the follow-up from KMTNet and LCO. A binary-lens single-source (2L1S) analysis reveals a planet/host mass ratio of $q = (0.72 \pm 0.07) \times 10^{-4}$, and the single-lens binary-source (1L2S) model is excluded by $\Delta\chi^2 = 80$. A Bayesian analysis using a Galactic model yields estimates of the host star mass of $M_{\rm host} = 0.57^{+0.33}_{-0.29}~M_\odot$, the planetary mass of $M_{\rm planet} = 13.5_{-6.8}^{+8.1}~M_{\oplus}$, and the lens distance of $D_{\rm L} = 6.9_{-1.7}^{+0.8}$ kpc. The projected planet-host separation of $a_\perp = 2.3_{-0.5}^{+0.5}$ au or $a_\perp = 3.2_{-0.8}^{+0.7}$, subject to the close/wide degeneracy. We also find that without the follow-up data, the survey-only data cannot break the degeneracy of central/resonant caustics and the degeneracy of 2L1S/1L2S models, showing the importance of follow-up observations for current microlensing surveys.Comment: PASP submitted. arXiv admin note: text overlap with arXiv:2301.0677