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
Plasma doping method and plasma doping apparatus
Device and method to automatically configure port forwarding
Hybrid interconnect scheme including aluminum metal line in low-k dielectric
Apparatus for generating electrical energy from rocking activated energy
Reliable and accurate usage detection of a software application
Aggregating completion messages in a sideband interface
Vehicle wheel rim protector
  Randomly Featured Patents
Spectroscopic instruments and methods employing array detector and variable filtering
Embedded pipe hanger
Method and system for the prevention of unwanted wireless telecommunications
Liquid crystal device with plural polymer network films
Hand-operated valve with locking mechanism
System and method for private wireless networks
Verotoxin pharmaceutical compositions and medical treatments therewith
Transfer base substrate and method of semiconductor device
Biological compositions and methods for treatment of lung cancer
Air conditioning system