A howling removing apparatus connectable to a microphone and a speaker, the howling removing apparatus comprising: a nonlinear converter configured to nonlinearly convert a sound signal to be input to the speaker and output a nonlinear signal; a delay unit configured to delay the sound signal by a fixed time and output a delayed signal; a norm calculator configured to calculate a norm from the delayed signal; a filter updater configured to update, when an average sound pressure level of a signal that is based on the sound signal is smaller than a threshold value, by using the nonlinear signal, the delayed signal, and the norm, an adaptive filter coefficient of an adaptive filter that simulates a transfer characteristic of a space where the sound signal is reproduced from the speaker and is returned to the microphone; a filter initializer configured to initialize the adaptive filter coefficient, when the average sound pressure level of the signal that is based on the sound signal exceeds the threshold value, wherein the signal that is based on the sound signal is the sound signal or the delayed signal; a cancel signal generator configured to convolve, when the average sound pressure level is smaller than the threshold value, the delayed signal and the adaptive filter coefficient updated by the filter updater with each other and thereby to generate a cancel signal, and configured to convolve, when the average sound pressure level is larger than the threshold value, the delayed signal and the adaptive filter coefficient initialized by the filter initializer with each other and thereby to generate the cancel signal, or configured to set, when the average sound pressure level is larger than the threshold value, the cancel signal to 0; and a subtracter configured to subtract the cancel signal from an input signal to be received from said microphone, to form said sound signal. a nonlinear converter configured to nonlinearly convert a sound signal to be input to the speaker and output a nonlinear signal; a delay unit configured to delay the sound signal by a fixed time and output a delayed signal; a norm calculator configured to calculate a norm from the delayed signal; a filter updater configured to update, when an average sound pressure level of a signal that is based on the sound signal is smaller than a threshold value, by using the nonlinear signal, the delayed signal, and the norm, an adaptive filter coefficient of an adaptive filter that simulates a transfer characteristic of a space where the sound signal is reproduced from the speaker and is returned to the microphone; a filter initializer configured to initialize the adaptive filter coefficient, when the average sound pressure level of the signal that is based on the sound signal exceeds the threshold value, wherein the signal that is based on the sound signal is the sound signal or the delayed signal; a cancel signal generator configured to convolve, when the average sound pressure level is smaller than the threshold value, the delayed signal and the adaptive filter coefficient updated by the filter updater with each other and thereby to generate a cancel signal, and configured to convolve, when the average sound pressure level is larger than the threshold value, the delayed signal and the adaptive filter coefficient initialized by the filter initializer with each other and thereby to generate the cancel signal, or configured to set, when the average sound pressure level is larger than the threshold value, the cancel signal to 0; and a subtracter configured to subtract the cancel signal from an input signal to be received from said microphone, to form said sound signal. <EOS>