For such digital lines a call shall be established to another telephony device, known as the ‘secondary device’. While applying the continuous RF disturbances to the EUT, the acoustic output from the secondary device (the received audio signals from the EUT) shall be measured using the method given in A.2.2 (See example test setup given in Figure A.6). Where lossless acoustic coupling to the secondary device cannot be achieved then the method of A.2.3 shall be used (See example test setup in Figure A.7). The limit levels defined in Table A.2 or A.3 shall be applied to the respective method. It is acceptable to perform the test twice: once while monitoring the demodulated audio levels, and again while evaluating other performance criteria.