Lingering cancellation for data encoded audio signals

An apparatus, comprising:

• a microphone configured to receive a data encoded audio signal that includes modulated digital data therein and to convert the data encoded audio signal into an electrical signal;
• a demodulator configured to demodulate the electrical signal obtained from the data encoded audio signal to produce frequency signals including a target frequency and a lingering effect of a previously received data encoded audio signal;
• and
• a lingering cancellation module configured to:
• select a set of one or more frequencies in the frequency signals with amplitudes above a predetermined threshold to produce a present input signal;
• compute an intersection value representing an intersection of the present input signal with a previous input signal generated from a previously received data encoded audio signal, the previous input signal generated from the previously received data encoded audio signal by selecting a set of one or more frequencies with amplitudes above the predetermined threshold from frequency signals demodulated from the previously received data encoded audio signal;
• based on the intersection value, calculate a difference value;
• and
• based on the difference value, select either a previous output signal generated from the previously received data encoded audio signal or the difference value as the present output signal.

A method, comprising:

• receiving a first data encoded audio signal that includes modulated digital data therein;
• demodulating the first data encoded audio signal to produce frequency signals including a target frequency and a lingering effect of a previously received data encoded audio signal;
• selecting a set of one or more frequencies in the frequency signals with amplitudes above a predetermined threshold to produce a present input signal;
• computing an intersection value, wherein the intersection value is the intersection of the present input signal with a previous input signal generated from a previously received data encoded audio signal by selecting a set of one or more frequencies with amplitudes above the predetermined threshold from frequency signals demodulated from the previously received data encoded audio signal;
• and
• determining a present output signal based on the intersection value.