Search results
Results from the WOW.Com Content Network
There are many methods available and beat detection is always a tradeoff between accuracy and speed. Beat detectors are common in music visualization software such as some media player plugins. The algorithms used may utilize simple statistical models based on sound energy or may involve sophisticated comb filter networks or other
The Foster–Seeley discriminator is a widely used FM detector. The detector consists of a special center-tapped transformer feeding two diodes in a full wave DC rectifier circuit. [2] [3] When the input transformer is tuned to the signal frequency, the output of the discriminator is zero. When there is no deviation of the carrier, both halves ...
Frequency domain, polyphonic detection is possible, usually utilizing the periodogram to convert the signal to an estimate of the frequency spectrum [4].This requires more processing power as the desired accuracy increases, although the well-known efficiency of the FFT, a key part of the periodogram algorithm, makes it suitably efficient for many purposes.
Sound recognition is a technology, which is based on both traditional pattern recognition theories and audio signal analysis methods. Sound recognition technologies contain preliminary data processing, feature extraction and classification algorithms. Sound recognition can classify feature vectors.
The radio frequency (RF) signal from the tuned circuit (bandpass filter) is amplified, then passes through the high pass filter to the demodulator, which extracts the audio frequency (AF) signal from the carrier wave. The audio signal is added back into the input of the amplifier, and is amplified again. At the output of the amplifier the audio ...
In the detector the two frequencies add and subtract, and a beat frequency in the audio range results at the difference between them: f audio = |f IF - f BFO | which sounds like a tone in the receiver's speaker. During the pulses of carrier, the beat frequency is generated, while between the pulses there is no carrier so no tone is produced.
Demodulation is the process of extracting the original information-bearing signal from a carrier wave.A demodulator is an electronic circuit (or computer program in a software-defined radio) that is used to recover the information content from the modulated carrier wave. [1]
Most audio compression techniques will make radical changes to the binary encoding of an audio file, without radically affecting the way it is perceived by the human ear. A robust acoustic fingerprint will allow a recording to be identified after it has gone through such compression, even if the audio quality has been reduced significantly.