The invention relates to a method of determining an impedance function IF of a load LS driven by an
amplifier AM, said method comprising the steps of providing a
digital audio signal DAS to said
amplifier AM, measuring one of either a current
signal representation CSR of current provided to said load LS by said
amplifier AM or a
voltage signal representation VSR of
voltage provided to said load LS by said amplifier AM, determining a
digital signal representation DSR on the basis of said
digital audio signal DAS, and determining said impedance function IF of said load LS on the basis of said
digital signal representation DSR and said measured one of either said current signal representation CSR or said
voltage signal representation VSR. The invention further relates to a load monitoring amplifier comprising amplification means AM comprising an amplifier input AI for receiving a
digital audio signal DAS and an amplifier output AO for delivering an amplified signal to a load LS and an analog reading point AR establishing one of either a current signal representation CSR by measuring the current of said amplified signal delivered to said load LS or a voltage signal representation VSR by measuring the voltage of said amplified signal delivered to said load LS, said load monitoring amplifier further comprising a
digital reading point DR for determining a
digital signal representation DSR on the basis of said digital
audio signal DAS and a monitoring means MM for determining an impedance function IF of said load LS on the basis of said digital signal representation DSR and said one of either said current signal representation CSR or said voltage signal representation VSR.