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

Real-time and interactive tools for vocal training based on an analytic signal with a cosine series envelope

We introduce real-time and interactive tools for assisting vocal training. In this presentation, we demonstrate mainly a tool based on real-time visualizer of fundamental frequency candidates to provide information-rich feedback to learners. The visualizer uses an efficient algorithm using analytic signals for deriving phase-based attributes. We start using these tools in vocal training for assisting learners to acquire the awareness of appropriate vocalization. The first author made the MATLAB implementation of the tools open-source. The code and associated video materials are accessible in the first author's GitHub repository.Comment: 4 pages, 6 figures, APSIPA ASC 201

Simultaneous Measurement of Multiple Acoustic Attributes Using Structured Periodic Test Signals Including Music and Other Sound Materials

We introduce a general framework for measuring acoustic properties such as liner time-invariant (LTI) response, signal-dependent time-invariant (SDTI) component, and random and time-varying (RTV) component simultaneously using structured periodic test signals. The framework also enables music pieces and other sound materials as test signals by "safeguarding" them by adding slight deterministic "noise." Measurement using swept-sin, MLS (Maxim Length Sequence), and their variants are special cases of the proposed framework. We implemented interactive and real-time measuring tools based on this framework and made them open-source. Furthermore, we applied this framework to assess pitch extractors objectively.Comment: 8 pages, 17 figures, accepted for APSIPA ASC 202

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

Asymmetric Synthesis of α‐Amino Phosphonic Acids using Stable Imino Phosphonate as a Universal Precursor

A practical method for synthesizing chiral α-amino phosphonic acid derivatives was developed. Readily available and stable N-o-nitrophenylsulfenyl (Nps) imino phosphonate was utilized as a substrate for a highly enantioselective Friedel–Crafts-type addition of indole or pyrrole nucleophiles catalyzed by chiral phosphoric acid. The resulting adduct was easily converted to N-9-fluorenylmethyloxycarbonyl (Fmoc) amino phosphonic acid, which is useful for synthesizing peptides containing an amino phosphonic acid

Three-dimensional structure of monoanionic methionine-enkephalin: X-ray structure of tert-butyloxycarbonyl-Tyr-Gly-Gly-(4-bromo)Phe-Met-OH

AbstractThe conformation of tert-butyloxycarbonyl-Tyr-Gly-Gly-(4-bromo)Phe-Met-OH, as a monoanionic derivative of Met-enkephalin, was elucidated by X-ray crystal analysis. The molecule took an extended conformation which was bended at the Phe residue. The implication of the dimer formation caused by 4 intermolecular hydrogen bonds was discussed in the relation with the opiate receptor

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

Are you laughing, smiling or crying?

Acoustic, articulatory, and perceptual analyses of spontaneous laughing, smiling, and crying speech were done in comparison with neutral speech. Listeners were asked to rate the emotional intensity and identify the emotion as happy, sad, or neutral (or other/unknown) of auditorily presented (a) phrases and (b) single words. The results show acoustic, articulatory and perceptual similarities for laughing, smiling and crying speech; smiling speech was sometimes judged as sad. Utterances rated as emotionally intense (whether laughing, smiling, or crying speech) are characterized by high F0, high F2 and low H2 (dB) (especially for happy), and tended to be produced with raised/retracted upper lip, and lowered tongue dorsum. Possible reasons for the phonetic similarities in such divergent types of emotional expressions, e.g., laughing, smiling and crying, are discussed. Also, discussed are possible reasons why phonetic characteristics of speech intended by the speaker to be emotional are different from those perceived by listeners.APSIPA ASC 2009: Asia-Pacific Signal and Information Processing Association, 2009 Annual Summit and Conference. 4-7 October 2009. Sapporo, Japan. Oral session: Synthesis of Various Affective Speech Based on Knowledge of Human (6 October 2009)