freqz

HRTF frequency response

Since R2024a

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    Syntax

    [h,f] = freqz(s)
    [h,f] = freqz(s,Name=Value)
    freqz(___)

    Description

    [h,f] = freqz(s) returns the complex frequency response and the frequency vector of the first measurement of the HRTF data.

    example

    [h,f] = freqz(s,Name=Value) specifies options using one or more name-value arguments.

    example

    freqz(___) with no output arguments plots the frequency response.

    example

    Examples

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    Open Live Script

    Read in a SOFA file containing HRTF measurements.

    s = sofaread("ReferenceHRTF.sofa");

    Use freqz to compute the frequency response of the first measurement for the first receiver.

    [h,f] = freqz(s);

    Call freqz with no output arguments to plot the frequency response of the first measurement for the first receiver.

    freqz(s)

    Figure contains an axes object. The axes object with xlabel Frequency (Hz), ylabel Magnitude (dB) contains an object of type line. This object represents Measurement 1. Receiver 1.

    Open Live Script

    Read in a SOFA file containing HRTF measurements.

    s = sofaread("ReferenceHRTF.sofa");

    Select the HRTF measurements in the sagittal plane at a lateral angle of 45 degrees. Plot the frequency responses of the second receiver for these measurements.

    idx = findMeasurements(s,Plane="sagittal",PlaneOffsetAngle=45);
freqz(s,MeasurementIndex=idx,Receiver=2)
legend(Location="southeast")

    Figure contains an axes object. The axes object with xlabel Frequency (Hz), ylabel Magnitude (dB) contains 12 objects of type line. These objects represent Measurement 238. Receiver 2, Measurement 1008. Receiver 2, Measurement 239. Receiver 2, Measurement 1010. Receiver 2, Measurement 240. Receiver 2, Measurement 1134. Receiver 2, Measurement 1159. Receiver 2, Measurement 1176. Receiver 2, Measurement 1198. Receiver 2, Measurement 1323. Receiver 2, Measurement 557. Receiver 2, Measurement 1320. Receiver 2.

    Input Arguments

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    SOFA object, specified as one of the following objects.

    Name-Value Arguments

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    Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

    Example: freqz(s,NPoints=1024)

    Indices of measurements to use for the frequency response, specified as a vector of positive integers. The indices must correspond to measurements in the data of the SOFA object s.

    Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

    Indices of the receivers to use for the frequency response, specified as a vector of positive integers.

    Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

    Number of points in the frequency response, specified as a positive integer. For SimpleFreeFieldHRIR objects, the default value is max(2048,L), where L is the length of the HRTF impulse responses. For SimpleFreeFieldHRSOS objects, the default value is 2048.

    This argument does not apply to SimpleFreeFieldHRTF objects.

    Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

    Output Arguments

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    Complex frequency response of the HRTF data, returned as an N-by-M-by-R array, where:

    • N is the length of the frequency response.

    • M is the number of selected measurements defined by MeasurementIndex.

    • R is the number of selected receivers defined by Receiver.

    Frequencies in Hz corresponding to the frequency response, returned as a vector of length N, where N is the length of the frequency response.

    Version History

    Introduced in R2024a

    See Also

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