Method and apparatus for adjusting frequency characteristic of signal

A frequency characteristic adjustment apparatus, comprising:

• an adjustment device configured to divide an audio signal inputted from outside the apparatus into a signal component falling into one fixed-level band and one or more signal components falling into one or more variable-level bands and to adjust levels of the signal components in only the variable-level bands of the audio signal;
• and
• an output device configured to output the audio signal adjusted by the adjustment device,
• wherein the adjustment device is configured to assign, to the fixed-level band, a predetermined frequency band in which changes in sound pressure are sensitive to human audibility and to divide the inputted audio signal.

A program, carried out by a computer, for adjusting a frequency characteristic of an inputted signal so that the frequency characteristic of the signal agrees with a target frequency characteristic, the program making the computer have the functions of:

• receiving the inputted signal;
• dividing the inputted signal into a signal component falling into a one fixed-level band and one or more signal components falling into one or more variable-level bands;
• estimating a relative level of the signal component in each variable-level band on the basis of a level of the signal component in the fixed-level band in the target frequency characteristic;
• adjusting the level of the signal component of each variable-level band of the signal based on the estimated relative level of the signal component in each variable-level band;
• and
• outputting the adjusted signal.

A program, carried out by a computer, for adjusting a frequency characteristic of an inputted audio signal so that the frequency characteristic of the signal agrees with a target frequency characteristic, the program making the computer have the functions of:

• receiving the inputted audio signal;
• dividing the received audio signal into a signal component falling into one fixed-level band and one or more signal components falling into one or more variable-level bands, a predetermined frequency band in which changes in sound pressure are sensitive to human audibility being assigned to the fixed-level band;
• adjusting levels of the signal components in only the variable-level bands of the audio signal;
• and
• outputting the adjusted audio signal.

A method of adjusting a frequency characteristic of an inputted signal so that the frequency characteristic of the signal agrees with a target frequency characteristic, the method comprising the steps of:

• receiving the inputted signal;
• dividing the received signal into a signal component falling into a one fixed-level band and one or more signal components falling into one or more variable-level bands;
• estimating a relative level of the signal component in each variable-level band on the basis of a level of the signal component in the fixed-level band in the target frequency characteristic;
• adjusting the level of the signal component of each variable-level band of the signal based on the estimated relative level of the signal component in each variable-level band;
• and
• outputting the signal adjusted by the adjustment step.

A method of adjusting a frequency characteristic of an inputted audio signal so that the frequency characteristic of the audio signal agrees with a target frequency characteristic, the method comprising the steps of:

• receiving the inputted audio signal;
• dividing the received audio signal into a signal component falling into one fixed-level band and one or more signal components falling into one or more variable-level bands, a predetermined frequency band in which changes in sound pressure are sensitive to human audibility being assigned to the fixed-level band;
• adjusting levels of the signal components in only the variable-level bands of the audio signal;
• and
• outputting the audio signal adjusted by the adjustment step.