Earpiece

An earpiece, comprising:

• a body having an acoustic driver and an output aperture;
• a sealing structure extending from a region adjacent the output aperture to hold the output aperture adjacent to the entrance to the user's ear canal;
• an acoustic nozzle extending from the acoustic driver toward the output aperture, the acoustic nozzle including an acoustic passage between an entrance aperture and the output aperture to conduct sound waves from the acoustic driver toward the output aperture, the acoustic passage having a proximal end adjacent the acoustic driver and a distal end toward the output aperture;
• first acoustic impedance at the proximal end of the acoustic nozzle;
• and
• second acoustic impedance at the distal end of the acoustic nozzle;
• wherein the acoustic nozzle has a nozzle volume between the first acoustic impedance and the second acoustic impedance, the first acoustic impedance, second acoustic impedance, and nozzle volume being selected to control resonance in the user's ear canal when the sealing structure is engaged with the entrance to the user's ear canal;
• and wherein the first acoustic impedance has a different acoustic impedance value than the second acoustic impedance.

An acoustic nozzle for an earpiece, comprising:

• an acoustic passage to conduct sound waves from an acoustic driver toward an output aperture, the acoustic passage having a proximal end configured to be adjacent the acoustic driver and a distal end configured to be adjacent the output aperture;
• first acoustic impedance means at the proximal end of the acoustic nozzle;
• and
• second acoustic impedance means at the distal end of the acoustic nozzle;
• wherein the acoustic nozzle has a nozzle volume between the first acoustic impedance and the second acoustic impedance, the first acoustic impedance, second acoustic impedance, and nozzle volume being selected to control resonance in a first frequency band centered at approximately 3 KHz and in a second frequency band centered at approximately 6 KHz.