edu.cmu.sphinx.frontend.frequencywarp

Class FrequencyWarper

java.lang.Object

edu.cmu.sphinx.frontend.frequencywarp.FrequencyWarper

public class FrequencyWarper
extends java.lang.Object

Defines the Bark frequency warping function. This class provides methods to convert frequencies from a linear scale to the bark scale. The bark scale is originated from measurements of the critical bandwidth. Please find more details in books about psychoacoustics or speech analysis/recognition.

Constructor Summary

Constructors

Constructor and Description
FrequencyWarper()

Method Summary

Modifier and Type	Method and Description
double	barkToHertz(double bark) Compute linear frequency in Hertz from Bark frequency.
double	hertzToBark(double hertz) Compute Bark frequency from linear frequency in Hertz.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FrequencyWarper

public FrequencyWarper()

Method Detail

hertzToBark

public double hertzToBark(double hertz)

Compute Bark frequency from linear frequency in Hertz. The function is: bark = 6.0*log(hertz/600 + sqrt((hertz/600)^2 + 1))

Parameters:

hertz - the input frequency in Hertz

Returns:

the frequency in a Bark scale

barkToHertz

public double barkToHertz(double bark)

Compute linear frequency in Hertz from Bark frequency. The function is: hertz = 300*(exp(bark/6.0) - exp(-bark/6.0))

Parameters:

bark - the input frequency in Barks

Returns:

the frequency in Hertz