A pitch state dependent dictionary design method for single-channel speech separation

Author(s):  
Haiyan Guo ◽  
Zhen Yang ◽  
Linghua Zhang ◽  
Lei Ye
2009 ◽  
Author(s):  
M. H. Radfar ◽  
W. -Y. Chan ◽  
R. M. Dansereau ◽  
W. Wong

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Dazhi Jiang ◽  
Zhihui He ◽  
Yingqing Lin ◽  
Yifei Chen ◽  
Linyan Xu

As network supporting devices and sensors in the Internet of Things are leaping forward, countless real-world data will be generated for human intelligent applications. Speech sensor networks, an important part of the Internet of Things, have numerous application needs. Indeed, the sensor data can further help intelligent applications to provide higher quality services, whereas this data may involve considerable noise data. Accordingly, speech signal processing method should be urgently implemented to acquire low-noise and effective speech data. Blind source separation and enhancement technique refer to one of the representative methods. However, in the unsupervised complex environment, in the only presence of a single-channel signal, many technical challenges are imposed on achieving single-channel and multiperson mixed speech separation. For this reason, this study develops an unsupervised speech separation method CNMF+JADE, i.e., a hybrid method combined with Convolutional Non-Negative Matrix Factorization and Joint Approximative Diagonalization of Eigenmatrix. Moreover, an adaptive wavelet transform-based speech enhancement technique is proposed, capable of adaptively and effectively enhancing the separated speech signal. The proposed method is aimed at yielding a general and efficient speech processing algorithm for the data acquired by speech sensors. As revealed from the experimental results, in the TIMIT speech sources, the proposed method can effectively extract the target speaker from the mixed speech with a tiny training sample. The algorithm is highly general and robust, capable of technically supporting the processing of speech signal acquired by most speech sensors.


2003 ◽  
Vol 122 (3) ◽  
pp. 277-294 ◽  
Author(s):  
Alessio Accardi ◽  
Michael Pusch

The Torpedo Cl− channel, CLC-0, is inhibited by clofibric acid derivatives from the intracellular side. We used the slow gate-deficient mutant CLC-0C212S to investigate the mechanism of block by the clofibric acid–derivative p-chlorophenoxy-acetic acid (CPA). CPA blocks open channels with low affinity (KDO= 45 mM at 0 mV) and shows fast dissociation (koff = 490 s−1 at −140 mV). In contrast, the blocker binds to closed channels with higher affinity and with much slower kinetics. This state-dependent block coupled with the voltage dependence of the gating transitions results in a highly voltage-dependent inhibition of macroscopic currents (KD ∼1 mM at −140 mV; KD ∼65 mM at 60 mV). The large difference in CPA affinity of the open and closed state suggests that channel opening involves more than just a local conformational rearrangement. On the other hand, in a recent work (Dutzler, R., E.B. Campbell, and R. MacKinnon. 2003. Science. 300:108–112) it was proposed that the conformational change underlying channel opening is limited to a movement of a single side chain. A prediction of this latter model is that mutations that influence CPA binding to the channel should affect the affinities for an open and closed channel in a similar manner since the general structure of the pore remains largely unchanged. To test this hypothesis we introduced point mutations in four residues (S123, T471, Y512, and K519) that lie close to the intracellular pore mouth or to the putative selectivity filter. Mutation T471S alters CPA binding exclusively to closed channels. Pronounced effects on the open channel block are observed in three other mutants, S123T, Y512A, and K519Q. Together, these results collectively suggest that the structure of the CPA binding site is different in the open and closed state. Finally, replacement of Tyr 512, a residue directly coordinating the central Cl− ion in the crystal structure, with Phe or Ala has very little effect on single channel conductance and selectivity. These observations suggest that channel opening in CLC-0 consists in more than a movement of a side chain and that other parts of the channel and of the selectivity filter are probably involved.


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