Magnetic field antenna

1. A magnetic field antenna comprising:

a) an earplug body having a distal end and a proximal end;

b) a magnetic core section within the earplug body;

c) an antenna coil having at least one turn wrapped at least partially around the magnetic core section;

d) at least one electrical component within the earplug body, electrically coupled to the antenna coil; and

e) an eartip adapter at least partially made of magnetic material, located on the proximal end of the earplug body, the eartip adapter being magnetically coupled to the magnetic core section and acoustically coupled to the at least one electrical component.

2. The magnetic field antenna of claim 1 , further comprising a magnetic shunt magnetically coupled to the magnetic core section and to the eartip adapter, at least partially magnetically shunting the at least one electrical component to provide at least partial magnetic shielding of the at least one electrical component.

3. The magnetic field antenna of claim 2 , in which the earplug body has an outer surface comprising a cover adjacent the distal end of the earplug body and a base adjacent the proximal end of the earplug body, and the magnetic shunt forms at least part of the base.

4. The magnetic field antenna of claim 3 , in which the magnetic core section and the magnetic shunt comprise a single part made of magnetic material.

5. The magnetic field antenna of claim 1 , in which the antenna coil is located such that at least one turn of the antenna coil, projected into a perpendicular field axis plane, circumscribes an area that overlaps at least an area of the at least one electrical component projected onto the perpendicular field axis plane.

6. The magnetic field antenna of claim 1 , in which the at least one electrical component comprises a speaker.

7. The magnetic field antenna of claim 1 , in which the at least one electrical component comprises at least one passive electronic component.

8. The magnetic field antenna of claim 7 , in which the passive electronic component comprises a capacitor connected in parallel with the antenna coil.

9. The magnetic field antenna of claim 1 , in which the at least one electrical component comprises a microphone.

10. The magnetic field antenna of claim 1 , further comprising a loop transmitter comprising a coil of wire.

11. The magnetic field antenna of claim 1 , further comprising a molded eartip mounted on the eartip adapter.

12. A magnetic field antenna comprising:

a) a body at least partially of magnetic material, having a distal end and a proximal end;

b) a magnetic core section within the body adjacent to the distal end;

c) an antenna coil having at least one turn wrapped at least partially around the magnetic core section; and

d) at least one electrical component within the body, electrically coupled to the antenna coil;

wherein the antenna coil is located such that at least one turn of the antenna coil, projected into a perpendicular field axis plane, circumscribes an area that overlaps at least an area of the at least one electrical component projected onto the perpendicular field axis plane.

13. The magnetic field antenna of claim 12 , further comprising a magnetic shunt magnetically coupled to the magnetic core section, at least partially magnetically shunting the at least one electrical component to provide at least partial magnetic shielding of the at least one electrical component.

14. The magnetic field antenna of claim 13 , in which the magnetic core section and the magnetic shunt comprise a single part made of magnetic material.

15. The magnetic field antenna of claim 13 , in which the body has an outer surface and the magnetic shunt forms at least part of the outer surface.

16. The magnetic field antenna of claim 12 , in which the at least one electrical component comprises a speaker.

17. The magnetic field antenna of claim 12 , in which the at least one electrical component comprises at least one passive electronic component.

18. The magnetic field antenna of claim 17 , in which the passive electronic component comprises a capacitor connected in parallel with the antenna coil.

19. The magnetic field antenna of claim 12 , in which the at least one electrical component comprises a microphone.

20. The magnetic field antenna of claim 12 , further comprising an eartip adapter on the proximal end of the body, acoustically coupled to the at least one electrical component.

21. The magnetic field antenna of claim 20 , further comprising a molded eartip mounted on the eartip adapter.

22. A wireless earplug comprising:

a) an earplug body having a distal end and a proximal end and an outer surface comprising a mechanical barrier adjacent the distal end of the earplug body and a base adjacent the proximal end of the earplug body;

b) a magnetic core section within the earplug body inside the mechanical barrier;

c) an antenna coil having at least one turn wrapped at least partially around the magnetic core section;

d) a speaker having a speaker output, located within the earplug body and electrically coupled to the antenna coil;

e) a magnetic shunt magnetically coupled to the magnetic core section, at least partially enclosing the speaker to provide at least partial magnetic shielding of the speaker; and

f) an eartip adapter at least partially made of magnetic material, located on the proximal end of the earplug body, the eartip adapter being magnetically coupled to the magnetic shunt and acoustically coupled to the speaker output.

23. The earplug of claim 22 , in which the magnetic shunt forms at least part of the base.

24. The earplug of claim 22 , further comprising a molded eartip mounted on the eartip adapter.

25. The earplug of claim 22 , further comprising a loop transmitter comprising a coil of wire.