Apparatus and method for generating a filtered audio signal realizing elevation rendering

A system comprising:

• an apparatus for generating an filtered audio signal from an audio input signal,
• wherein the filter unit is configured to filter the audio input signal to acquire a binaural audio signal as the filtered audio signal comprising exactly two audio channels depending on the filter information,
• wherein the filter information determiner is configured to receive input information on an input head-related transfer function, and
• wherein the filter information determiner is configured to determine the filter information by determining a modified head-related transfer function by modifying the input head-related transfer function depending on the selected filter curve or depending on the modified filter curve;
• an apparatus for providing direction modification information, wherein the apparatus for providing direction modification information comprises:
• a plurality of loudspeakers, wherein each of the plurality of loudspeakers is configured to replay a replayed audio signal, wherein a first one of the plurality of loudspeakers is located at a first position at a first height, and wherein second one of the of the plurality of loudspeakers is located at a second position being different from the first position at a second height, being different from the first height,
• two microphones, each of the two microphones being configured to record a recorded audio signal by receiving sound waves from each loudspeaker of the plurality of loudspeakers emitted by said loudspeaker when replaying the audio signal,
• a binaural room impulse response determiner being configured to determine a plurality of binaural room impulse responses by determining a binaural room impulse response for each loudspeaker of the plurality of loudspeakers depending on the replayed audio signal being replayed by said loudspeaker and depending on each of the recorded audio signals being recorded by each of the two microphones when said replayed audio signal is replayed by said loudspeaker, and
• a filter curve generator being configured to generate at least one filter curve depending on two of the plurality of binaural room impulse responses,
• wherein the direction modification information depends on the at least one filter curve,
• wherein the filter information determiner of the apparatus for generating an filtered audio signal from an audio input signal is configured to determine filter information using selecting, depending on input height information, a selected filter curve from a plurality of filter curves, or
• wherein the filter information determiner of the apparatus for generating an filtered audio signal from an audio input signal is configured to determine the filter information using determining a modified filter curve by modifying a reference filter curve depending on the elevation information,
• wherein direction modification information provided by the apparatus for providing direction modification information comprises the plurality of filter curves or the reference filter curve.

An apparatus for providing direction modification information, wherein the apparatus comprises:

• a plurality of loudspeakers, wherein each of the plurality of loudspeakers is configured to replay a replayed audio signal, wherein a first one of the plurality of loudspeakers is located at a first position at a first height, and wherein second one of the of the plurality of loudspeakers is located at a second position being different from the first position, at a second height, being different from the first height,
• two microphones, each of the two microphones being configured to record a recorded audio signal by receiving sound waves from each loudspeaker of the plurality of loudspeakers emitted by said loudspeaker when replaying the audio signal,
• a binaural room impulse response determiner being configured to determine a plurality of binaural room impulse responses by determining a binaural room impulse response for each loudspeaker of the plurality of loudspeakers depending on the replayed audio signal being replayed by said loudspeaker and depending on each of the recorded audio signals being recorded by each of the two microphones when said replayed audio signal is replayed by said loudspeaker, and
• a filter curve generator being configured to generate at least one filter curve depending on two of the plurality of binaural room impulse responses,
• wherein the direction modification information depends on the at least one filter curve.

A method for generating a filtered audio signal from an audio input signal, wherein the method comprises:

• determining filter information depending on input height information wherein the input height information depends on a height of a virtual sound source, and
• filtering the audio input signal to acquire the filtered audio signal depending on the filter information,
• wherein determining the filter information is conducted using selecting, depending on the input height information, a selected filter curve from a plurality of filter curves, or
• wherein determining the filter information is conducted using determining a modified filter curve by modifying a reference filter curve depending on the elevation information.

A method for providing direction modification information, wherein the method comprises:

• for each loudspeaker of a plurality of loudspeakers, replaying a replayed audio signal by said loudspeaker and recording sound waves emitted from said loudspeaker when replaying said replayed audio signal by two microphones to acquire a recorded audio signal for each of the two microphones, wherein a first one of the plurality of loudspeakers is located at a first position at a first height, and wherein second one of the of the plurality of loudspeakers is located at a second position being different from the first position, at a second height, being different from the first height,
• determining a plurality of binaural room impulse responses by determining a binaural room impulse response for each loudspeaker of the plurality of loudspeakers depending on the replayed audio signal being replayed by said loudspeaker and depending on each of the recorded audio signals being recorded by each of the two microphones when said replayed audio signal is replayed by said loudspeaker, and
• generating at least one filter curve depending on two of the plurality of binaural room impulse responses,
• wherein the direction modification information depends on the at least one filter curve.

A non-transitory digital storage medium having a computer program stored thereon to perform the method for generating a filtered audio signal from an audio input signal, said method comprising:

• determining filter information depending on input height information wherein the input height information depends on a height of a virtual sound source, and
• filtering the audio input signal to acquire the filtered audio signal depending on the filter information,
• wherein determining the filter information is conducted using selecting, depending on the input height information, a selected filter curve from a plurality of filter curves, or
• wherein determining the filter information is conducted using determining a modified filter curve by modifying a reference filter curve depending on the elevation information;
• when said computer program is run by a computer.

A non-transitory digital storage medium having a computer program stored thereon to perform the method for providing direction modification information, said method comprising:

• for each loudspeaker of a plurality of loudspeakers, replaying a replayed audio signal by said loudspeaker and recording sound waves emitted from said loudspeaker when replaying said replayed audio signal by two microphones to acquire a recorded audio signal for each of the two microphones, wherein a first one of the plurality of loudspeakers is located at a first position at a first height, and wherein second one of the of the plurality of loudspeakers is located at a second position being different from the first position, at a second height, being different from the first height,
• determining a plurality of binaural room impulse responses by determining a binaural room impulse response for each loudspeaker of the plurality of loudspeakers depending on the replayed audio signal being replayed by said loudspeaker and depending on each of the recorded audio signals being recorded by each of the two microphones when said replayed audio signal is replayed by said loudspeaker, and
• generating at least one filter curve depending on two of the plurality of binaural room impulse responses,
• wherein the direction modification information depends on the at least one filter curve;
• when said computer program is run by a computer.