A listening system, comprising: a handset apparatus, comprising: a first loudspeaker; a first microphone (40, 42); noise reduction circuitry (52, 54, 56); an external receptor provided with connector detection means; a first interface, connected to said first loudspeaker and said first microphone (40, 42); a second interface connected to said external receptor; a selection switch, configured to connect said noise reduction circuitry (52, 54, 56) either to said first interface or said second interface; control means, connected to the connector detection means; and a user interface; and a listening device (62, 63), comprising: at least one second microphone (66, 67); at least one second loudspeaker (64, 65); and a connector, adapted to be connected with said external receptor, wherein the noise reduction circuitry (52, 54, 56) is configured to apply a noise reduction transfer function to a signal supplied thereto to generate a noise cancellation signal, and characterised in that: said connector detection means is configured to cause the control means to select the first interface so that a signal generated by the first microphone (40, 42) in response to ambient noise is supplied to the noise reduction circuitry and the noise cancellation signal generated by the noise reduction circuitry is supplied to the first loudspeaker if no connector is inserted into the external receptor and to cause said control means to select the second interface so that a signal generated by the second microphone (66, 67) in response to ambient noise is supplied to the noise reduction circuitry and the noise cancellation signal generated by the noise reduction circuitry is supplied to the second loudspeaker if the connector is inserted into the external receptor; and the noise reduction transfer function applied by the noise reduction circuitry is user selectable or user adjustable by means of the user interface on the handset apparatus. a handset apparatus, comprising: a first loudspeaker; a first microphone (40, 42); noise reduction circuitry (52, 54, 56); an external receptor provided with connector detection means; a first interface, connected to said first loudspeaker and said first microphone (40, 42); a second interface connected to said external receptor; a selection switch, configured to connect said noise reduction circuitry (52, 54, 56) either to said first interface or said second interface; control means, connected to the connector detection means; and a user interface; and a first loudspeaker; a first microphone (40, 42); noise reduction circuitry (52, 54, 56); an external receptor provided with connector detection means; a first interface, connected to said first loudspeaker and said first microphone (40, 42); a second interface connected to said external receptor; a selection switch, configured to connect said noise reduction circuitry (52, 54, 56) either to said first interface or said second interface; control means, connected to the connector detection means; and a user interface; and a listening device (62, 63), comprising: at least one second microphone (66, 67); at least one second loudspeaker (64, 65); and a connector, adapted to be connected with said external receptor, at least one second microphone (66, 67); at least one second loudspeaker (64, 65); and a connector, adapted to be connected with said external receptor, wherein the noise reduction circuitry (52, 54, 56) is configured to apply a noise reduction transfer function to a signal supplied thereto to generate a noise cancellation signal, and characterised in that: said connector detection means is configured to cause the control means to select the first interface so that a signal generated by the first microphone (40, 42) in response to ambient noise is supplied to the noise reduction circuitry and the noise cancellation signal generated by the noise reduction circuitry is supplied to the first loudspeaker if no connector is inserted into the external receptor and to cause said control means to select the second interface so that a signal generated by the second microphone (66, 67) in response to ambient noise is supplied to the noise reduction circuitry and the noise cancellation signal generated by the noise reduction circuitry is supplied to the second loudspeaker if the connector is inserted into the external receptor; and the noise reduction transfer function applied by the noise reduction circuitry is user selectable or user adjustable by means of the user interface on the handset apparatus.