Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
Pitch detection apparatus










Image Number 5 for United States Patent #4688464.

A pitch detector is disclosed that automatically recognizes the pitch of musical notes quickly and outputs the pitch information in a variety of formats. The detector employs a microprocessor that samples the signal from a musical instrument or voice at regular intervals using an analog-to-digital converter and then utilizes both amplitude and time information from the waveform to determine the fundamental period of the note, while rejecting the harmonic components. The microprocessor analyzes the waveform looking for peaks that are approximately equal in amplitude separated by opposite polarity peaks. The time intervals between the peaks must be approximately equal too. Timing information is measured using more than one point on the waveform to avoid inaccuracies caused by temporary distortions of the waveform. The timing points are chosen at points where the slope of the waveform is high for substantially optimal accuracy. To filter out erroneous readings caused by pitch detection during note transition or noise, additional processing of the data is performed to cause a second corroborating reading to be taken when a note transition that is uncommon musically is detected.








 
 
  Recently Added Patents
Method and apparatus for performing real time anomaly detection
Automated dynamic differential data processing
Polyester resin for toner, electrostatic charge image developing toner, electrostatic charge image developer, toner cartridge, process cartridge, image forming apparatus, and image forming met
Method of analyzing cell structures and their components
Vehicle seating system and method for reducing fatigue with changing actuator movement
Broadband optical network apparatus and method
Semiconductor thin film, thin film transistor, method for manufacturing same, and manufacturing equipment of semiconductor thin film
  Randomly Featured Patents
Methods and apparatus to process cache allocation requests based on priority
Precision contour gage
System and method for mixing at least four components
Spin-current switchable magnetic memory element and method of fabricating the memory element
Process for making oxide dispersion-strengthened tungsten heavy alloy by mechanical alloying
Signal processor having feedback loop control for decision feedback equalizer
Deoxy and oxygen-substituted sugar-containing 14-aminosteroid compounds
Military patrol cap form insert set
Footwear with articulating outsole lugs
Electric reflector lamp for use with IEC standard