Hiroko Kato Solvang

Learn More
This paper addresses the problem of voice activity detection in noise environments. The proposed voice activity detection technique described in this paper is based on a statistical model approach, and estimates the statistical models sequentially without a prior knowledge of noise. The crucial factor as regards the statistical model-based approach is noise(More)
In frequency-domain blind source separation (BSS) for speech with independent component analysis (ICA), a practical parametric Pearson distribution system is used to model the distribution of frequency-domain source signals. ICA adaptation rules have a score function determined by an approximated signal distribution. Approximation based on the data may(More)
This paper proposes a feature for voice activity detection (VAD) obtained from a speech signal analysis that uses the exponential autoregressive (ExpAR) model. This model employs exponential terms that depend on the amplitude of observed signals in the AR coefficients part. Since these terms can model the nonlinearity of speech caused by the nonlinear(More)
This paper proposes a speech signal analysis approach that uses the exponential autoregressive (ExpAR) model. In real speech signal, the amplitude and frequency are fluctuating randomly. These fluctuations are non-Gaussian and have nonlinear dynamics. This means that they cannot be modeled adequately with linear AR models or compositions of sine/cosine(More)
This paper describes a longitudinal analysis of the vowel development of a Japanese female infant between the ages of 4 and 60 months. The speech data were natural spontaneous speech recorded for at least an hour per month. Vowels were extracted from the data according to their phoneme labels by two transcribers. The two lower spectral peaks of the vowels(More)
In the marine environment, where there are few absolute physical barriers, contemporary contact between previously isolated species can occur across great distances, and in some cases, may be inter-oceanic. An example of this can be seen in the minke whale species complex. Antarctic minke whales are genetically and morphologically distinct from the common(More)
Inferring the number of genetically distinct populations and their levels of connectivity is of key importance for the sustainable management and conservation of wildlife. This represents an extra challenge in the marine environment where there are few physical barriers to gene-flow, and populations may overlap in time and space. Several studies have(More)
The common minke whale (Balaenoptera acutorostrata acutorostrata) is a boreo-arctic species, and the summer period is generally characterized by intensive feeding and consequently seasonal fattening at high latitudes. The fat deposited is stored as energy reserves for overwintering at lower latitudes where feeding is greatly reduced. It is therefore(More)
  • 1