One or more embodiments describe controlling audio signals at a user device during a communication session between the user device and a remote node, in which a primary audio signal is received at audio input means of the user device for transmission to the remote node in the communication session. It is determined whether the user device is operating in a first or a second mode. In dependence upon determining that the user device is operating in the first mode, the secondary audio signals are selectively suppressed from being output from the user device during the communication session.