A method of controlling audio signals at a user device during a communication session between the user device and a remote node, the method comprising the steps of: receiving a primary audio signal at audio input means of the user device for transmission to the remote node in the communication session; determining whether the user device is operating in a first mode in which secondary audio signals output from the user device are likely to disturb the primary audio signal received at the audio input means, in that, when output from the user device at an operational volume, the secondary audio signals are received at the audio input means with a signal strength above a threshold; or a second mode in which secondary audio signals output from the user device are not likely to disturb the primary audio signal received at the audio input means, in that, when output from the user device at said operational volume, the secondary audio signals are received at the audio input means with a signal strength not above said threshold; and selectively suppressing the secondary audio signals during the communication session, in dependence upon determining that the user device is operating in the first mode, and not suppressing the secondary audio signals from being output from the user device during the communication session if it is determined that the user device is operating in the second mode; the method being characterised in that: said secondary audio signals do not include audio data received from the remote node in the communication session; and said step of selectively suppressing the secondary audio signals during the communication session comprises selectively suppressing the secondary audio signals from being output from the user device during the communication session. receiving a primary audio signal at audio input means of the user device for transmission to the remote node in the communication session; determining whether the user device is operating in a first mode in which secondary audio signals output from the user device are likely to disturb the primary audio signal received at the audio input means, in that, when output from the user device at an operational volume, the secondary audio signals are received at the audio input means with a signal strength above a threshold; or a second mode in which secondary audio signals output from the user device are not likely to disturb the primary audio signal received at the audio input means, in that, when output from the user device at said operational volume, the secondary audio signals are received at the audio input means with a signal strength not above said threshold; and selectively suppressing the secondary audio signals during the communication session, in dependence upon determining that the user device is operating in the first mode, and not suppressing the secondary audio signals from being output from the user device during the communication session if it is determined that the user device is operating in the second mode; the method being characterised in that: said secondary audio signals do not include audio data received from the remote node in the communication session; and said step of selectively suppressing the secondary audio signals during the communication session comprises selectively suppressing the secondary audio signals from being output from the user device during the communication session. said secondary audio signals do not include audio data received from the remote node in the communication session; and said step of selectively suppressing the secondary audio signals during the communication session comprises selectively suppressing the secondary audio signals from being output from the user device during the communication session.