Hearing aid having improved RF immunity to RF electromagnetic interference produced from a wireless communications device

• US 20070121979A1
• Filed: 11/30/2005
• Published: 05/31/2007
• Est. Priority Date: 11/30/2005
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Mankaruse, George, Zhu, Lizhong, Corrigan, Michael
• Granted Patent: US 7,715,578 B2
• Time in Patent Office: Days
• US Class Current: 381/315
• CPC Class Codes: H04R 25/505 using digital signal processing
• CPC Class Codes: Y10T 29/49005 Acoustic transducer

Abstract

A hearing aid has improved immunity to RF electromagnetic interference produced from wireless communications devices. A microphone receives audio signals from the environment. Audio circuitry is connected to the microphone and amplifies the audio signals. A speaker is connected to the audio circuitry and directs the audio signals into an ear canal of the user of the hearing aid. The audio connection lines connect the microphone and audio circuitry and the speaker and audio circuitry. A filter is connected into each of the audio connection lines and operative for reducing the RF coupling from a wireless communications device.

Claims

1. A hearing aid having improved immunity to RF electromagnetic interference produced from wireless communications devices comprising:

a microphone for receiving audio signals from the environment;

audio circuitry connected to the microphone for amplifying the audio signals;

a speaker connected to said audio circuitry for directing the audio signals into an ear of a user using the hearing aid, and further comprising audio connection lines connecting the microphone and audio circuitry and the speaker and audio circuitry; and

a filter connected into each of the audio connection lines and operative for reducing the RF coupling from a wireless communications device.

2. A hearing aid according to claim 1, wherein a filter is serially connected into each audio connection line.

3. A hearing aid according to claim 1, wherein a filter comprises a ferrite inductor.

4. A hearing aid according to claim 1, wherein a filter comprises a ferrite bead.

5. A hearing aid according to claim 1, wherein a filter comprises an LC filter serially connected into each audio connection line.

6. A hearing aid according to claim 1, and further comprising a second filter element connected into an audio connection line connected to said speaker, and serially connected to a filter connected into the audio connection line.

7. A hearing aid according to claim 6, wherein said second filter element comprises a ferrite inductor.

8. A hearing aid according to claim 1, and further comprising an RF shield surrounding one of at least the speaker or microphone to aid in reducing the RF coupling from a mobile wireless communications device.

9. A hearing aid according to claim 8, wherein said RF shield comprises a metallic housing.

10. A hearing aid according to claim 1, and further comprising a hearing aid housing that supports said microphone, speaker and audio circuitry.

11. A hearing aid according to claim 10, and further comprising a tone hook connected to said hearing aid housing for receiving audio signals from the speaker, and an earmold connected to said tone hook and adapted to be inserted within the ear of a user.

12. A hearing aid having improved immunity to RF electromagnetic interference produced from wireless communications devices comprising:

a microphone for receiving audio signals from the environment;

audio circuitry connected to the microphone for amplifying the audio signals, said audio circuitry including a digital signal processor (DSP) and microprocessor connected to said DSP;

a speaker connected to said audio circuitry for directing the audio signals into an ear of a user using the hearing aid, and further comprising audio connection lines connecting the microphone and audio circuitry and the speaker and audio circuitry, and microphone bias lines connecting the microprocessor and microphone for carrying microphone bias control signals between the microprocessor and the microphone;

a filter connected to each of the audio connection lines connecting the speaker and microphone and operative for reducing the RF coupling from a wireless communications device; and

a microphone bias filter connected into the microphone bias lines for reducing the RF coupling from a wireless communications device.

13. A hearing aid according to claim 12, wherein said microphone bias filter comprises a serial inductor or shunt capacitor.

14. A hearing aid according to claim 12, wherein said microphone bias filter comprises a ferrite bead.

15. A hearing aid according to claim 12, wherein said microphone bias filter comprises a ground connected capacitor connected into each microphone bias line.

16. A hearing aid according to claim 12, wherein a filter comprises a ferrite inductor.

17. A hearing aid according to claim 12, wherein a filter comprises a ferrite bead.

18. A hearing aid according to claim 12, which comprises wherein a filter comprises an LC filter serially connected into each audio connection line.

19. A method of making a hearing aid having improved immunity to RF electromagnetic interference produced from wireless communications devices, which comprises:

providing a microphone for receiving audio signals from the environment, audio circuitry connected to the microphone for amplifying the audio signals, and a speaker connected to said audio circuitry for directing the audio signals into an ear canal of a user of the hearing aid, comprising audio connection lines connecting the microphone and audio circuitry and the speaker and audio circuitry; and

reducing the RF coupling from a wireless communications device by connecting a filter into audio connection lines that connect the speaker and microphone with the audio circuitry.

20. A method according to claim 19, which further comprises enclosing one of at least the microphone or speaker within an RF shield for reducing the RF coupling from a mobile wireless communications device.

21. A method according to claim 19, which further comprises connecting a filter serially into an audio connection line.

22. A method according to claim 19, which further comprises connecting a ferrite bead into an audio connection line.

23. A method according to claim 19, which further comprises connecting a microphone bias filter into microphone bias lines that pass microphone bias control signals between the audio circuitry and the microphone.