Concealment of intermittent mono reception of FM stereo radio receivers

A method for determining a parametric stereo parameter from a two-channel audio signal and configured to process frames of the two-channel audio signal using the parametric stereo parameter to generate a noise reduced two-channel audio signal;

• the method comprising:
• determining a first parametric stereo parameter based on a first frame of the received two-channel audio signal;
• determining an energy of a side signal within the first signal frame;
• wherein the side signal is obtainable from the two-channel audio signal and wherein the energy is above a high threshold;
• determining a number of following successive signal frames during which the energy of the side signal drops from a value above the high threshold to a value below a low threshold;
• determining that the two-channel audio signal following the first signal frame is a forced mono signal if the number of successive signal frames is below a frame threshold;
• and
• determining the parametric stereo parameter for the processing of frames of the two-channel audio signal succeeding the first signal frame based on the first parametric stereo parameter, if it is determined that the two-channel audio signal following the first signal frame is a forced mono signal,
• wherein the method is carried out by one or more processors and/or one or memory devices.

An apparatus for determining a parametric stereo parameter from a two-channel audio signal and configured to process frames of the two-channel audio signal using the parametric stereo parameter to generate a noise reduced two-channel audio signal, comprising:

• at least one processor;
• and
• at least one memory storing a computer program;
• in which the at least one memory with the computer program is configured with the at least one processor to cause the apparatus to at least:
• determining a first parametric stereo parameter based on a first frame of the received two-channel audio signal;
• determining an energy of a side signal within the first signal frame;
• wherein the side signal is obtainable from the two-channel audio signal and wherein the energy is above a high threshold;
• determining a number of following successive signal frames during which the energy of the side signal drops from a value above the high threshold to a value below a low threshold;
• determining that the two-channel audio signal following the first signal frame is a forced mono signal if the number of successive signal frames is below a frame threshold;
• and
• determining the parametric stereo parameter for the processing of frames of the two-channel audio signal succeeding the first signal frame based on the first parametric stereo parameter, if it is determined that the two-channel audio signal following the first signal frame is a forced mono signal,
• wherein the method is carried out by one or more processors and/or one or memory devices.