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
Fused thiazole derivatives as kinase inhibitors
Vehicle, toy, and/or replicas thereof
Method of and apparatus for evaluating an optimal irradiation amount of an electron beam for drawing a pattern onto a sample
Methods and devices for enforcing network access control utilizing secure packet tagging
Method and system for updating device management application meter read logic
Smooth silicon-containing films
Determination of copy number variations using binomial probability calculations
  Randomly Featured Patents
One mask PNP (or NPN) transistor allowing high performance
Cosmetic compositions containing amino-multicarboxylate modified starch
Method for assigning frequencies to base stations of a mobile telephone network
Method and tool for machining the surfaces of workpieces
Pressed glass bowl
Access catheter and method for maintaining separation between a falloposcope and a tubal wall
Organic light emitting device with constant luminance
Athletic practice gloves
Solar radiation detection unit and vehicle air conditioner using the same
Power combiner, polarizer and structure including a waveguide section rotated by a stepper motor arrangement