Systems and methods for using a piezoelectric speaker as a microphone in a mobile device

A method comprising:

• generating, by a piezoelectric speaker, a first signal, the first signal induced at least in part by sound incident on the piezoelectric speaker other than sound generated by the piezoelectric speaker;
• receiving a second signal from a microphone, the second signal induced by sound incident on the microphone;
• processing at least one of the first signal and the second signal to determine at least one characteristic of sound incident upon at least one of the piezoelectric speaker and the microphone;
• and
• selecting at least one of the microphone and the piezoelectric speaker as a signal source for incident sound based on the at least one characteristic.

An integrated circuit comprising:

• a first input configured to receive a first signal from a piezoelectric speaker, the first signal induced at least in part by sound incident on the piezoelectric speaker other than sound generated by the piezoelectric speaker;
• a second input configured to receive a second signal from a microphone, the second signal induced by sound incident on the microphone;
• and
• a processing circuit configured to:
• process at least one of the first signal and the second signal to determine at least one characteristic of sound incident upon at least one of the piezoelectric speaker and the microphone;
• and
• select at least one of the microphone and the piezoelectric speaker as a signal source for incident sound based on the at least one characteristic.

A method comprising:

• receiving a first signal from a piezoelectric speaker, the first signal induced at least in part by sound incident on the piezoelectric speaker other than sound generated by the piezoelectric speaker;
• receiving a second signal from a microphone, the second signal induced by sound incident on the microphone;
• processing at least one of the first signal and the second signal to determine at least one characteristic of sound incident upon at least one of the piezoelectric speaker and the microphone;
• and
• selecting one of the microphone and the piezoelectric speaker as a signal source for incident sound based on the characteristic.

An integrated circuit comprising:

• a first input configured to receive a first signal from a first speaker comprising a piezoelectric speaker, the first signal induced at least in part by sound incident on the first speaker other than sound generated by the first speaker;
• a second input configured to receive a second signal from the first speaker, the second signal induced at least in part by sound incident on the second speaker other than sound generated by the second speaker;
• and
• a processing circuit configured to:
• process at least one of the first signal and the second signal to determine at least one characteristic of sound incident on at least one of the first speaker and the second speaker;
• select one of the first speaker and the second speaker as a signal source for incident sound based on the at least one characteristic;
• and
• select the other one of the first speaker and the second speaker to generate sound based on the at least one characteristic.

A method comprising:

• receiving a first signal from a first speaker comprising a piezoelectric speaker, the first signal induced at least in part by sound incident on the first speaker other than sound generated by the first speaker;
• receiving a second signal from a second speaker, the second signal induced at least in part by sound incident on the second speaker other than sound generated by the second speaker;
• processing at least one of the first signal and the second signal to determine at least one characteristic of sound incident on at least one of the first speaker and the second speaker;
• selecting one of the first speaker and the second speaker as a signal source for incident sound based on the at least one characteristic;
• and
• selecting the other one of the first speaker and the second speaker to generate sound based on the at least one characteristic.