Head-related transfer function

A method for presenting audio signals to a user with an audio device, the audio device having a speaker system including a speaker for presenting an audio signal at a location adjacent the user and another speaker for presenting another audio signal at another location adjacent the user, the method comprising:

• determining a current position of a virtual object with respect to the user, the virtual object having an associated audio track;
• identifying a current audio zone from a plurality of audio zones responsive to the determined current position, each of the plurality of audio zones having a corresponding predefined filter and another corresponding predefined filter, wherein each of the predefined filters for each of the plurality of audio zones is a corresponding set of digital biquadratic filters and each of the corresponding sets of digital biquadratic filters represents between 24 and 42 multiply-and-accumulate operations;
• and
• applying the predefined filters corresponding to the current audio zone to the audio track associated with the virtual object to produce the audio signal for presentation by the speaker and the other audio signal for presentation by the other speaker.

A non-transitory computer readable medium including instructions for presenting audio signals to a user with an audio device, the audio device having a speaker system including a speaker for presenting an audio signal at a location adjacent the user and another speaker for presenting another audio signal at another location adjacent the user, the instructions, when performed by a processor, configure the processor to:

• determine a current position of a virtual object with respect to the user, the virtual object having an associated audio track;
• identify a current audio zone from a plurality of audio zones responsive to the determined current position, each of the plurality of audio zones having a corresponding predefined filter and another corresponding predefined filter, wherein each of the predefined filters for each of the plurality of audio zones is a corresponding set of digital biquadratic filters and each of the corresponding sets of digital biquadratic filters represents between 24 and 42 multiply-and-accumulate operations;
• and
• apply the predefined filters corresponding to the current audio zone to the audio track associated with the virtual object to produce the audio signal for presentation by the speaker and the other audio signal for presentation by the other speaker.