Processor, out-of-head localization filter generation method, and program

An out-of-head localization filter generation method in a system, the system comprising:

• an output unit configured to be worn on a user and output sounds to an ear of the user;
• a built-in microphone embedded in the output unit;
• a data storage unit configured to store first preset data related to first ear canal transfer characteristics picked up by a built-in microphone embedded in the output unit and second preset data related to second ear canal transfer characteristics acquired in a state in which a person being measured wears an independent microphone that is independent from the output unit in association with each other, the data storage unit storing a plurality of first and second preset data acquired for a plurality of persons being measured, wherein
• in the data storage unit,
• the first and second preset data are clustered based on a conversion function between the first ear canal transfer characteristics and the second ear canal transfer characteristics,
• representative characteristics are calculated for each of clusters based on a plurality of first ear canal transfer characteristics that belong to the cluster,
• a representative conversion function is calculated for each cluster based on the plurality of conversion functions that belong to the cluster, and
• the out-of-head localization filter generation method comprises:
• an output step for outputting a measurement signal to each output unit worn on the user;
• a signal acquisition step for acquiring a sound pickup signal when the measurement signal output from the output unit toward the user's ear is picked up by a microphone unit worn on the ear of the user;
• a first frequency characteristics acquisition step for converting the sound pickup signal into a frequency domain and acquiring first frequency characteristics;
• a comparing step for comparing the first frequency characteristics with a plurality of representative characteristics;
• an extraction step for extracting the representative conversion function based on a comparison result in the comparing step;
• a second frequency characteristics calculation step for calculating second frequency characteristics by applying the extracted representative conversion function to the first frequency characteristics;
• and
• an inverse filter calculation step for calculating an inverse filter based on the second frequency characteristics.

A non-transitory computer readable medium storing a program for causing a computer to execute an out-of-head localization filter generation method, wherein

• the computer is able to access a data storage unit configured to store first preset data related to first ear canal transfer characteristics picked up by a built-in microphone embedded in an output unit and second preset data related to second ear canal transfer characteristics acquired in a state in which a person being measured wears an independent microphone that is independent from the output unit in association with each other, the data storage unit storing a plurality of first and second preset data acquired for a plurality of persons being measured,
• in the data storage unit,
• the first and second preset data are clustered based on a conversion function between the first ear canal transfer characteristics and the second ear canal transfer characteristics,
• representative characteristics are calculated for each of clusters based on a plurality of first ear canal transfer characteristics that belong to a cluster,
• a representative conversion function is calculated for each cluster based on the plurality of conversion functions that belong to the cluster, and
• the out-of-head localization filter generation method comprises:
• an output step for outputting a measurement signal to each output unit worn on the user;
• a signal acquisition step for acquiring a sound pickup signal when the measurement signal output from the output unit toward the user's ear is picked up by a microphone unit worn on the ear of the user;
• a first frequency characteristics acquisition step for converting the sound pickup signal into a frequency domain and acquiring first frequency characteristics;
• a comparing step for comparing the first frequency characteristics with a plurality of representative characteristics;
• an extraction step for extracting the representative conversion function based on a comparison result in the comparing step;
• a second frequency characteristics calculation step for calculating second frequency characteristics by applying the extracted representative conversion function to the first frequency characteristics;
• and
• an inverse filter calculation step for calculating an inverse filter based on the second frequency characteristics.