Programmer Guide/Command Reference/EVAL/hth - Revision history

193.171.195.48 at 09:49, 21 April 2011

2011-04-21T09:49:42Z

← Older revision		Revision as of 11:49, 21 April 2011
Line 1:		Line 1:
	{{DISPLAYTITLE:{{SUBPAGENAME}}}}		{{DISPLAYTITLE:{{SUBPAGENAME}}}}
	Compute spectral weights.		Compute spectral weights.

	;Usage: <code>hth(<var>f</var>, <var>type</var>)</code>		;Usage: <code>hth(<var>f</var>, <var>type</var>)</code>
	:;<var>f</var>:A scalar, vector or matrix containing the frequency value(s) in Hz.		:;<var>f</var>:A scalar, vector or matrix containing the frequency value(s) in Hz.
Line 7:		Line 6:
	;Result: The result ''w'' has the same type as the argument ''f'' and contains the values of the spectral weighting function selected by ''type''.		;Result: The result ''w'' has the same type as the argument ''f'' and contains the values of the spectral weighting function selected by ''type''.
	:<code>''w''[i,j] = '''weight'''(''f''[i,j],''type'')</code>		:<code>''w''[i,j] = '''weight'''(''f''[i,j],''type'')</code>

	:{\|		:{\|
	! ''type'' !! description !! result		! ''type'' !! description !! result
Line 27:		Line 25:
	::<code>L<sub>TH</sub>(f) = 3.64 * f^-0.8 - 6.5 * exp(-0.6 * (f - 3.3)^2) + 1e-3 * f^4</code>		::<code>L<sub>TH</sub>(f) = 3.64 * f^-0.8 - 6.5 * exp(-0.6 * (f - 3.3)^2) + 1e-3 * f^4</code>
	::<code>with: L<sub>TH</sub> = hearing threshold in dB, f = frequency in kHz</code>		::<code>with: L<sub>TH</sub> = hearing threshold in dB, f = frequency in kHz</code>
			;See also: [[../fft\|fft]], [[../window\|window]]

	~~;See also:~~ [[Programmer_Guide/Command_Reference/EVAL~~/fft\|fft]], [[Programmer_Guide/Command_Reference/EVAL/window~~\|~~window~~]]		[[Programmer_Guide/Command_Reference/EVAL#Functions\|<function list>]]


Line 47:		Line 46:
	#spe := eval lin2log(cr2len(fft(whanning($#sig)))) - hth(fill($#n/2+1,0,44100/$#n),2)		#spe := eval lin2log(cr2len(fft(whanning($#sig)))) - hth(fill($#n/2+1,0,44100/$#n),2)
	</pre>		</pre>


	~~[[Programmer_Guide/Command_Reference/EVAL#Functions\|<function list>]]~~

Toni at 11:07, 11 April 2011

2011-04-11T11:07:09Z

← Older revision		Revision as of 13:07, 11 April 2011
Line 5:		Line 5:
	:;<var>f</var>:A scalar, vector or matrix containing the frequency value(s) in Hz.		:;<var>f</var>:A scalar, vector or matrix containing the frequency value(s) in Hz.
	:;<var>type</var>:The type of the spectral weight to be computed.		:;<var>type</var>:The type of the spectral weight to be computed.
	;Result: The result ''w'' has the same type as the argument ''f'' and contains the values of the spectral weighting function selected by ''type'' (''w''[i,j] = '''weight'''(''f''[i,j],''type'')).		;Result: The result ''w'' has the same type as the argument ''f'' and contains the values of the spectral weighting function selected by ''type''.
			:<code>''w''[i,j] = '''weight'''(''f''[i,j],''type'')</code>

	:{\|		:{\|

Toni at 11:06, 11 April 2011

2011-04-11T11:06:17Z

← Older revision		Revision as of 13:06, 11 April 2011
Line 16:		Line 16:
	\| 2 \|\| value of the '''A''' weighting function in dB \|\| L<sub>A</sub>		\| 2 \|\| value of the '''A''' weighting function in dB \|\| L<sub>A</sub>
	\|-		\|-
	\| 3 \|\| '''A''' weighting ~~value~~ \|\| 10^(-L<sub>A</sub> / 20)		\| 3 \|\| '''A''' weighting factor \|\| 10^(-L<sub>A</sub> / 20)
	\|-		\|-
	\| 4 \|\| value of the '''C''' weighting function in dB \|\| L<sub>C</sub>		\| 4 \|\| value of the '''C''' weighting function in dB \|\| L<sub>C</sub>
	\|-		\|-
	\| 5 \|\| '''C''' weighting ~~value~~ \|\| 10^(-L<sub>C</sub> / 20)		\| 5 \|\| '''C''' weighting factor \|\| 10^(-L<sub>C</sub> / 20)
	\|-		\|-
	\|}		\|}

Toni at 11:05, 11 April 2011

2011-04-11T11:05:07Z

← Older revision		Revision as of 13:05, 11 April 2011
Line 5:		Line 5:
	:;<var>f</var>:A scalar, vector or matrix containing the frequency value(s) in Hz.		:;<var>f</var>:A scalar, vector or matrix containing the frequency value(s) in Hz.
	:;<var>type</var>:The type of the spectral weight to be computed.		:;<var>type</var>:The type of the spectral weight to be computed.
	:;Result: The result ''w'' has the same type as the argument ''f'' and contains the values of the spectral weighting function selected by ''type'' (''w''[i,j] = '''weight'''(''f''[i,j],''type'')).		;Result: The result ''w'' has the same type as the argument ''f'' and contains the values of the spectral weighting function selected by ''type'' (''w''[i,j] = '''weight'''(''f''[i,j],''type'')).

	::{\|		:{\|
	! ''type'' !! description !! result		! ''type'' !! description !! result
	\|-		\|-
Line 23:		Line 23:
	\|-		\|-
	\|}		\|}
	::For L<sub>TH</sub> the algorithm published by E.Terhardt (JASA 71(3), March 1982) is used:		:For L<sub>TH</sub> the algorithm published by E.Terhardt (JASA 71(3), March 1982) is used:
	:::<code>L<sub>TH</sub>(f) = 3.64 * f^-0.8 - 6.5 * exp(-0.6 * (f - 3.3)^2) + 1e-3 * f^4</code>		::<code>L<sub>TH</sub>(f) = 3.64 * f^-0.8 - 6.5 * exp(-0.6 * (f - 3.3)^2) + 1e-3 * f^4</code>
	:::<code>with: L<sub>TH</sub> = hearing threshold in dB, f = frequency in kHz</code>		::<code>with: L<sub>TH</sub> = hearing threshold in dB, f = frequency in kHz</code>

	;See also: [[Programmer_Guide/Command_Reference/EVAL/fft\|fft]], [[Programmer_Guide/Command_Reference/EVAL/window\|window]]		;See also: [[Programmer_Guide/Command_Reference/EVAL/fft\|fft]], [[Programmer_Guide/Command_Reference/EVAL/window\|window]]

Toni at 11:04, 11 April 2011

2011-04-11T11:04:48Z

← Older revision		Revision as of 13:04, 11 April 2011
Line 4:		Line 4:
	;Usage: <code>hth(<var>f</var>, <var>type</var>)</code>		;Usage: <code>hth(<var>f</var>, <var>type</var>)</code>
	:;<var>f</var>:A scalar, vector or matrix containing the frequency value(s) in Hz.		:;<var>f</var>:A scalar, vector or matrix containing the frequency value(s) in Hz.
	;<var>type</var>:The type of the spectral weight to be computed.		:;<var>type</var>:The type of the spectral weight to be computed.
	:;Result: The result ''w'' has the same type as the argument ''f'' and contains the values of the spectral weighting function selected by ''type'' (''w''[i,j] = '''weight'''(''f''[i,j],''type'')).		:;Result: The result ''w'' has the same type as the argument ''f'' and contains the values of the spectral weighting function selected by ''type'' (''w''[i,j] = '''weight'''(''f''[i,j],''type'')).

Toni at 11:04, 11 April 2011

2011-04-11T11:04:16Z

← Older revision		Revision as of 13:04, 11 April 2011
Line 24:		Line 24:
	\|}		\|}
	::For L<sub>TH</sub> the algorithm published by E.Terhardt (JASA 71(3), March 1982) is used:		::For L<sub>TH</sub> the algorithm published by E.Terhardt (JASA 71(3), March 1982) is used:
	:::<L><sub>TH</sub>(f) = 3.64 * f^-0.8 - 6.5 * exp(-0.6 * (f - 3.3)^2) + 1e-3 * f^4		:::<code>L<sub>TH</sub>(f) = 3.64 * f^-0.8 - 6.5 * exp(-0.6 * (f - 3.3)^2) + 1e-3 * f^4</code>
	:::(L<sub>TH</sub> in dB, f in kHz)		:::<code>with: L<sub>TH</sub> = hearing threshold in dB, f = frequency in kHz</code>

	;See also: [[Programmer_Guide/Command_Reference/EVAL/fft\|fft]], [[Programmer_Guide/Command_Reference/EVAL/window\|window]]		;See also: [[Programmer_Guide/Command_Reference/EVAL/fft\|fft]], [[Programmer_Guide/Command_Reference/EVAL/window\|window]]

Toni at 11:03, 11 April 2011

2011-04-11T11:03:08Z

Show changes

Toni at 10:35, 11 April 2011

2011-04-11T10:35:44Z

← Older revision		Revision as of 12:35, 11 April 2011
Line 1:		Line 1:
			{{DISPLAYTITLE:{{SUBPAGENAME}}}}
			Compute spectral weights.

			;Usage: <code>hth(<var>f</var>, <var>type</var>)</code>
			:;<var>f</var>:A scalar, vector or matrix containing the frequency value(s) in Hz.
			;<var>type</var>:The type of the spectral weight to be computed.
			:;Result: The result ''w'' has the same type as the argument ''f'' and contains the values of the spectral weighting function selected by ''type'' (''w''[i,j] = '''weight'''(''f''[i,j],''type'')).

			::{\|
			! ''type'' !! description !! [[1]]
			\|-
			\| 0 \|\| hearing threshold in dB \|\| \|\| <pre>w[i] = 1</pre>
			\|-
			\| 1 \|\| '''hanning''' \|\| not used \|\| <code>whanning(''x''{,''scale''})</code>
			\| <pre>w[i] = 0.5 - 0.5 * cos( a*i )
			with: a = 2 * pi / (n-1)</pre>
			\|-
			\| 2 \|\| '''hamming''' \|\| not used \|\| <code>whamming(''x''{,''scale''})</code>
			\| <pre>w[i] = 0.54 - 0.46 * cos( a*i )
			with: a = 2 * pi / (n-1)</pre>
			\|-
			\| 3 \|\| '''blackman''' \|\| 0<''par''<=0.25<BR>default=0.16 \|\| <code>wblackman(''x''{,''scale''{,''par''}})</code>
			\| <pre>w[i] = (1-par)/2 - 0.5 * cos( ai ) + par/2 cos( 2ai )
			with: a = 2 * pi / (n-1)</pre>
			\|-
			\| 4 \|\| '''kaiser''' \|\| 0<''par''<BR>default=8 \|\| <code>wkaiser(''x''{,''scale''{,''par''}})</code>
			\| <pre>w[i] = I0( par / m * sqrt(m^2 - (i-m)^2) ) / I0( par )
			with: m = (n-1) / 2
			I0(z) is the modfied zero-order bessel function</pre>
			\|-
			\| 5 \|\| '''bartlett'''<BR>(triangle) \|\| not used \|\| <code>wbartlett(''x''{,''scale''})</code>
			\| <pre>0 <= i <= m: w[i] = i / m
			m < i < n: w[i] = 2 - i / m
			with: m = (n-1) / 2</pre>
			\|-
			\| 6 \|\| '''tappered rectangle''' \|\| not used \|\| <code>wtaprect(''x''{,''scale''})</code>
			\| A rectangle with to short hanning slopes.
			\|-
			\| 7 \|\| '''nuttall''' \|\| not used \|\| <code>wnuttall(''x''{,''scale''})</code>
			\| A 4-term blackman-harris window with high dynamic range, low frequency resolution and minimized maximum sidelobes.<BR>Nuttall, Albert H. "Some Windows with Very Good Sidelobe Behavior." IEEE Transactions on Acoustics, Speech, and Signal Processing. Vol. ASSP-29 (February 1981). pp. 84-91
			\|-
			\| 8 \|\| '''flat-top''' \|\| not used \|\| <code>wflattop(''x''{,''scale''})</code>
			\| A 5-term blackman-harris window with high dynamic range, low frequency resolution and minimized passband ripple (< 0.01dB). Flat-top windows are primarily used for calibration purposes.
			\|-
			\| 9 \|\| '''gauss''' \|\| 0<''par''<= 20<BR>default=3 \|\| <code>wgauss(''x''{,''scale''{,''par''}})</code>
			\| <pre>w[i] = exp( -0.5 * (par * (m - i) / m) ^ 2 )
			with: m = (n-1) / 2</pre>
			\|-
			\|}

			::Notes:
			::*If the argument ''type'' has an invalid value, the rectangle window is used.
			::*If the energy-correction is enabled (argument ''scale''!=0), the values w[i] scaled by a factor that approximately equalises the energy loss caused by the window function. The scaling factor is computed using white noise as test signal.
			::*If the argument ''par'' is supplied to a function not using this argument, it is ignored.

			;Result: The result ''r'' depends on the argument ''x'':
			:*x is a number: The value is used as window length ''n''. The result ''r'' is vector with length ''n'' containing the window function.
			:*x is a vector or matrix: The number of rows of ''x'' is used as window length. Each column of ''x'' is multiplied with the window function (element-wise) and stored in a column of ''r''. The result ''r'' has the same type as ''x''.


			;See also: [[Programmer_Guide/Command_Reference/EVAL/fft\|fft]], [[Programmer_Guide/Command_Reference/EVAL/hth\|hth]], [[Programmer_Guide/Command_Reference/EVAL/wconvert\|wconvert]]

			[[Programmer_Guide/Command_Reference/EVAL#Functions\|<function list>]]



	{{DISPLAYTITLE:{{SUBPAGENAME}}}}		{{DISPLAYTITLE:{{SUBPAGENAME}}}}
	=====hth=====		=====hth=====

Admin: 1 revision: Initial import

2010-11-18T16:31:41Z

1 revision: Initial import

← Older revision	Revision as of 18:31, 18 November 2010
(No difference)

193.171.195.8: initial import

2010-05-17T13:05:27Z

initial import

New page

{{DISPLAYTITLE:{{SUBPAGENAME}}}}
=====hth=====

Hearing Threshold Level (HTH) or A/C spectral weightings.

=====Usage:=====

<code>hth(<var>f</var>, <var>type</var>)</code>

;<var>f</var>

:The frequency (scalar, vector or matrix).

;<var>type</var>

:The type of weighting function. The following values are supported:

:<code>0</code> - Hearing threshold level

:<code>1</code> - Hearing threshold weighting factor

:<code>2</code> - A weighting levels.

:<code>3</code> - A weighting factors.

:<code>4</code> - C weighting levels.

:<code>5</code> - C weighting factors.

=====Notes:=====

Factor = 1 / (10^(Level/20))

=====Result:=====

The result of the requested function (same datatype as <var>f</var>).