39 research outputs found
A modulation property of time-frequency derivatives of filtered phase and its application to aperiodicity and fo estimation
We introduce a simple and linear SNR (strictly speaking, periodic to random
power ratio) estimator (0dB to 80dB without additional
calibration/linearization) for providing reliable descriptions of aperiodicity
in speech corpus. The main idea of this method is to estimate the background
random noise level without directly extracting the background noise. The
proposed method is applicable to a wide variety of time windowing functions
with very low sidelobe levels. The estimate combines the frequency derivative
and the time-frequency derivative of the mapping from filter center frequency
to the output instantaneous frequency. This procedure can replace the
periodicity detection and aperiodicity estimation subsystems of recently
introduced open source vocoder, YANG vocoder. Source code of MATLAB
implementation of this method will also be open sourced.Comment: 8 pages 9 figures, Submitted and accepted in Interspeech201
An objective test tool for pitch extractors' response attributes
We propose an objective measurement method for pitch extractors' responses to
frequency-modulated signals. It enables us to evaluate different pitch
extractors with unified criteria. The method uses extended time-stretched
pulses combined by binary orthogonal sequences. It provides simultaneous
measurement results consisting of the linear and the non-linear time-invariant
responses and random and time-varying responses. We tested representative pitch
extractors using fundamental frequencies spanning 80~Hz to 400~Hz with 1/48
octave steps and produced more than 1000 modulation frequency response plots.
We found that making scientific visualization by animating these plots enables
us to understand different pitch extractors' behavior at once. Such efficient
and effortless inspection is impossible by inspecting all individual plots. The
proposed measurement method with visualization leads to further improvement of
the performance of one of the extractors mentioned above. In other words, our
procedure turns the specific pitch extractor into the best reliable measuring
equipment that is crucial for scientific research. We open-sourced MATLAB codes
of the proposed objective measurement method and visualization procedure.Comment: 5 pages, 9 figures, submitted to Interspeech2022. arXiv admin note:
text overlap with arXiv:2111.0362
Frequency domain variant of Velvet noise and its application to acoustic measurements
We propose a new family of test signals for acoustic measurements such as
impulse response, nonlinearity, and the effects of background noise. The
proposed family complements difficulties in existing families, the Swept-Sine
(SS), pseudo-random noise such as the maximum length sequence (MLS). The
proposed family uses the frequency domain variant of the Velvet noise (FVN) as
its building block. An FVN is an impulse response of an all-pass filter and
yields the unit impulse when convolved with the time-reversed version of
itself. In this respect, FVN is a member of the time-stretched pulse (TSP) in
the broadest sense. The high degree of freedom in designing an FVN opens a vast
range of applications in acoustic measurement. We introduce the following
applications and their specific procedures, among other possibilities. They are
as follows. a) Spectrum shaping adaptive to background noise. b) Simultaneous
measurement of impulse responses of multiple acoustic paths. d) Simultaneous
measurement of linear and nonlinear components of an acoustic path. e)
Automatic procedure for time axis alignment of the source and the receiver when
they are using independent clocks in acoustic impulse response measurement. We
implemented a reference measurement tool equipped with all these procedures.
The MATLAB source code and related materials are open-sourced and placed in a
GitHub repository.Comment: 10 pages, 14 figures, APSIPA ASC 2019. arXiv admin note: text overlap
with arXiv:1806.0681
A Case of Gastroparesis after Cryoballoon Ablation followed by Medication-Induced Recovery within 6 Months
Atrial fibrillation (AF) is the most common cardiac arrhythmia, and cryoballoon ablation was developed as a new treatment modality for symptomatic AF. Gastroparesis is rarely reported as a transient complication of ablation, and its frequency and risk are not clear. We experienced a rare case of gastroparesis after cryoballoon ablation followed by medication-induced recovery within 6 months
Precocious Metamorphosis in the Juvenile Hormone–Deficient Mutant of the Silkworm, Bombyx mori
Insect molting and metamorphosis are intricately governed by two hormones, ecdysteroids and juvenile hormones (JHs). JHs prevent precocious metamorphosis and allow the larva to undergo multiple rounds of molting until it attains the proper size for metamorphosis. In the silkworm, Bombyx mori, several “moltinism” mutations have been identified that exhibit variations in the number of larval molts; however, none of them have been characterized molecularly. Here we report the identification and characterization of the gene responsible for the dimolting (mod) mutant that undergoes precocious metamorphosis with fewer larval–larval molts. We show that the mod mutation results in complete loss of JHs in the larval hemolymph and that the mutant phenotype can be rescued by topical application of a JH analog. We performed positional cloning of mod and found a null mutation in the cytochrome P450 gene CYP15C1 in the mod allele. We also demonstrated that CYP15C1 is specifically expressed in the corpus allatum, an endocrine organ that synthesizes and secretes JHs. Furthermore, a biochemical experiment showed that CYP15C1 epoxidizes farnesoic acid to JH acid in a highly stereospecific manner. Precocious metamorphosis of mod larvae was rescued when the wild-type allele of CYP15C1 was expressed in transgenic mod larvae using the GAL4/UAS system. Our data therefore reveal that CYP15C1 is the gene responsible for the mod mutation and is essential for JH biosynthesis. Remarkably, precocious larval–pupal transition in mod larvae does not occur in the first or second instar, suggesting that authentic epoxidized JHs are not essential in very young larvae of B. mori. Our identification of a JH–deficient mutant in this model insect will lead to a greater understanding of the molecular basis of the hormonal control of development and metamorphosis
Development of exploratory research tools based on TANDEM-STRAIGHT
This article introduces a new set of tools based on TANDEM-STRAIGHT, a fundamental reformulation of STRAIGHT, a speech analysis, modification and resynthesis system introduced in 1997. STRAIGHT has been used in a wide range of speech-related research as a flexible tool for implementing experiments and applications though its scientific foundation was not well established. TANDEM-STRAIGHT introduced a solid basis to resolve this difficulty while preserving the underlying concept of STRAIGHT. TANDEM is a procedure for estimating a temporally static power spectral representation of periodic signals. Together with this representation, the consistent sampling theory enabled complete reformulation of entire algorithms of STRAIGHT and led to a new implementation. This new implementation was applied to develop a set of new tools: temporally variable multi-aspect speech morphing tools, a graphical user interface (GUI) for manipulating STRAIGHT and morphing parameters, and procedures for preparing stimuli for perceptual experiments.APSIPA ASC 2009: Asia-Pacific Signal and Information Processing Association, 2009 Annual Summit and Conference. 4-7 October 2009. Sapporo, Japan. Oral session: Infrastructure Software for Speech Processing (5 October 2009)
Acappella Synthesis Demonstrations Using RWC Music Database - Application of auditory morphing based on STRAIGHT
A series of demonstrations of synthesized acappella songs based on an auditory morphing using STRAIGHT [5] will be presented. Singing voice data for morphing were extractedfromtheRWCmusicdatabaseofmusicalinstru - ment sound. Discussions on a new extension of the morphing procedure to deal with vibrato will be introduced based on the statistical analysis of the database and its e#ect on synthesized acappella will also be demonstrated