33results about How to "Maintain sound quality" patented technology

Techniques for multi-channel acoustic echo cancellation include adaptive filtering. An adaptive filter can use a lattice predictor of order M coupled to an adaptive LMS / Newton filter of length N, wherein M<N. The lattice predictor can provide decorrelation of the input to the LMS / Newton filter and can provide faster convergence for the LMS / Newton filter. Efficient operation of the LMS / Newton filter can also be provided by using output from the lattice predictor to provide low complexity update of weights for the LMS / Newton filter.

The present invention relates to acoustic properties of a terminal device of a telecommunication network. To improve the capability of the terminal device to maintain the sound quality good while the distance between the speaker and the ear changes, the enclosure of the terminal device is provided with means (71, 81) for conveying the acoustic waves generated backwards by the speaker (30) of the device inside the enclosure to a cavity-like antenna space (80) intended for the antenna of the terminal device.

An adjustable support 12 for a stringed musical instrument such as a cello 10 includes a shaft 14 that is removably inserted into the cello 10, and a support member 16 that is adjustably disposed upon and secured to the shaft 14. The support member 16 includes an insertion portion 26 with a stabilizing bushing 72 disposed thereupon for stabilized insertion into an aperture in a bottom portion 11 of the cello 10, an annular portion 28 with an annular wall 34 for engaging and supporting the bottom portion 11 of the cello 10, and a lower portion 30 for securing the support member 16 circumferentially about a cylindrical outer wall 18 of the shaft thereby allowing an artist playing the cello to select a comfortable elevated and stabilized position of the cello 10 above a floor surface.

To keep sounds emitted from a speaker apparatus in high quality. According to one embodiment of the present invention, a top layer and a back layer in a diaphragm of a speaker unit built in a speaker apparatus, and a reinforcement board for reinforcement which is interposed between the top layer and the back layer, and is disposed from the center part of diaphragm to the outer circumference part of diaphragm of the speaker diaphragm are provided. Thereby, unnecessary vibration caused by lack of the rigidity of the diaphragm can be prevented, and a possibility that the reinforcement board comes off or falls off can be remarkably reduced.

Provided are a fixed codebook search method based on iteration-free global pulse replacement in a speech codec, and a Code-Excited Linear-Prediction (CELP)-based speech codec using the method. The fixed codebook search method based on iteration-free global pulse replacement in a speech codec includes the steps of: (a) determining an initial codevector using a pulse-position likelihood vector or a correlation vector; (b) calculating a fixed-codebook search criterion value for the initial codevector; (c) calculating fixed-codebook search criterion values for respective codevectors obtained by replacing a pulse of the initial codevector each time for respective tracks, and determining a pulse position generating the largest fixed-codebook search criterion value as a candidate pulse position for the respective tracks, respectively; (d) calculating fixed-codebook search criterion values for respective codevectors of all combinations obtained by replacing at least one pulse position of the initial codevector with the candidate pulse positions of the respective tracks, and determining the largest value of the fixed-codebook search criterion values; and (e) comparing the fixed-codebook search criterion value for the initial codevector obtained in step (b) with the largest value determined in step (d) to determine an optimum fixed codevector.

Tonal musical instruments configured for outdoor installation are disclosed. The tonal musical instrument may comprise a support post, wherein the support post is configured for attachment to an outdoor surface, at least one a non-vibrating guard, a metal plate tuned to produce at least one note on a musical scale when struck by a user, and one or more fasteners securing the at least one non-vibrating guard and the metal plate to the support post.

Percussion instruments configured for outdoor installation are disclosed. The percussion instrument comprises a support post, wherein the support post is configured for attachment to an outdoor surface, a mounting base secured to the support post, one or more metal discs, wherein each metal disc is tuned to produce a note on a musical scale when struck by a user, and one or more fasteners securing the one or more metal discs to the mounting base.

The array microphone device has a microphone array composed of a plurality of microphone units, having a signal input section for inputting a signal from the microphone units to be corrected as a signal to be corrected; a reference signal input section; a gain variable section for making the levels of the signal to be corrected and the reference signal equal; and a gain control section. The gain control section includes a high-speed gain update section for changing the gain with a first amount of change per unit time upon time elapsed since the array microphone device is starting-up being below a predetermined period of time; and a low-speed gain update section for changing the gain with a second amount of change per unit time upon the elapsed time being above the predetermined period of time, the second amount of change being smaller than the first amount of change.

The invention relates to the technical field of piano overhauling, and discloses a piano string cleaning device. The piano string cleaning device comprises paired mounting plates, and the mounting plates are fixedly connected to a fixed plate. Movable plates are slidingly connected in the mounting plates, and opposite faces of the two movable plates are fixedly connected with an electric push rod.The end, away from the movable plates, of the electric push rod is fixedly connected with an arc-shaped plate. According to the piano string cleaning device and a use method thereof, the precision ofthe position of the whole device can be guaranteed when a piano string is cleaned, and piano string damage caused by device deviation is avoided. Removed debris and dust can fall into a collecting tank, the removed dust can be collected conveniently, and the dust is prevented from falling into the piano. A rotary cleaning plate can be driven to move while the piano string is cleaned so that the long piano string can be cleaned, and the piano string is cleaned more efficiently and conveniently.