An audio interface system is disclosed that receives an audio signal from an audio line and outputs a normalised audio signal. An audio interface device of the audio interface system comprises a signal conditioning module, a gain module to apply a gain to the audio signal and an attenuation module to apply an attenuation to the audio signal to output the normalised audio signal. The audio interface device further comprises an interface configured to communicate the normalised signal to an external device. In response to determining that an amplitude of the audio signal does not meet a minimum amplitude requirement or exceed a maximum amplitude requirement, the signal conditioning module is to adjust the amplitude of the audio signal by applying the gain and/or attenuation to meet the requirement.

An audio interface system is disclosed that receives an audio signal from an audio line and outputs a normalised audio signal. An audio interface device of the audio interface system comprises a signal conditioning module, a gain module to apply a gain to the audio signal and an attenuation module to apply an attenuation to the audio signal to output the normalised audio signal. The audio interface device further comprises an interface configured to communicate the normalised signal to an external device. In response to determining that an amplitude of the audio signal does not meet a minimum amplitude requirement or exceed a maximum amplitude requirement, the signal conditioning module is to adjust the amplitude of the audio signal by applying the gain and/or attenuation to meet the requirement.