Headset

• US 20100166203A1
• Filed: 03/19/2008
• Published: 07/01/2010
• Est. Priority Date: 03/19/2007
• Status: Abandoned Application

• Current Assignee: Sennheiser Electronic GmbH & Company KG
• Original Assignee: Sennheiser Electronic GmbH & Company KG
• Inventors: Wolter, Bjoern, Peissig, Juergen
• Application Number:
  US12/531,951
• Publication Number:
  US 20100166203A1
• Time in Patent Office: Days
• US Class Current: 381/71.600
• CPC Class Codes: G10K 11/17823 Reference signals, e.g. ambient acoustic environment
• CPC Class Codes: G10K 11/17825 Error signals
• CPC Class Codes: G10K 11/17854 the filter being an adaptive filter
• CPC Class Codes: G10K 11/17857 Geometric disposition, e.g. placement of microphones
• CPC Class Codes: G10K 11/17861 using additional means for damping sound, e.g. using sound absorbing panels
• CPC Class Codes: G10K 11/17881 the reference signal being an acoustic signal, e.g. recorded with a microphone
• CPC Class Codes: G10K 11/17885 additionally using a desired external signal, e.g. pass-through audio such as music or speech
• CPC Class Codes: G10K 2210/1081 Earphones, e.g. for telephones, ear protectors or headsets
• CPC Class Codes: G10K 2210/3016 Control strategies, e.g. energy minimization or intensity measurements
• CPC Class Codes: G10K 2210/3053 Speeding up computation or convergence, or decreasing the computational load
• CPC Class Codes: H04R 1/1083 Reduction of ambient noise active noise reduction per se G10K11/175; protective devices for the ear, e.g. providing acoustic protection A61F11/06
• CPC Class Codes: H04R 5/033 Headphones for stereophonic communication details thereof, e.g. relating to batteries, cables or control elements H04R1/10

Abstract

There is provided an earphone comprising a first housing (LK, AK, IK) for receiving an electroacoustic transducer and a second housing (RK, AK, IK) for receiving an electroacoustic reproduction transducer, at least one outer microphone (M1) for recording outside sound and at least one inner microphone (M2) for recording sound in the region between an ear of a user and the first and/or second housings (LK, RK, AK, IK). The earphone further comprises a digital active noise reduction unit (ANR) for performing active noise reduction based on the sound recorded by the at least one outer microphone and by the at least one inner microphone. The noise reduction unit (ANR) has an analysis unit (AU) for analyzing the sound recorded by the outer microphone and the inner microphone and for determining the signal types of the recorded sound. The noise reduction unit further comprises a plurality of signal processing units (SVE1-SVEn) which are respectively adapted to perform active noise reduction for a signal type. The analysis unit (AU) selects at least one of the signal processing units (SVE1-SVEn) for performing noise reduction based on the implemented analysis of the recorded sound.

Claims

1. An earphone comprising

a first housing (LK, AK, IK) for receiving an electroacoustic reproduction transducer and a second housing (RK, AK, IK) for receiving an electroacoustic reproduction transducer (L),

at least one outer microphone (M1) for recording outside sound,

at least one inner microphone (M2) for recording sound in the region between an ear of a user and the first or second housings (LK, RK, AK, IK), and

a digital active noise reduction unit (ANR) for performing active noise reduction based on the sound recorded by the at least one outer microphone and by the at least one inner microphone,

wherein the noise reduction unit (ANR) has an analysis unit (AU) for analyzing the sound recorded by the outer microphone and the inner microphone and for determining the signal types of the recorded sound and a plurality of signal processing units (SVE1-SVEn) which are respectively adapted to perform noise reduction for a signal type,

wherein the analysis unit (AU) selects at least one of the signal processing units (SVE1-SVEn) for performing noise reduction based on the implemented analysis of the recorded sound.

2. An earphone as set forth in claim 1 wherein the analysis unit (AU) is adapted to weight the output signals of the signal processing units (SVE1-SVEn).

3. An earphone as set forth in claim 1 wherein one of the signal processing units (SVE1-SVEn) has a feedforward path and a feedback path, wherein a first adaptive filter (F_FF(z)) is provided in the feedforward path,

wherein the signal processing unit (SVE1-SVEn) has a filter adaptation unit (FAE) for ascertaining the filter parameters of the first filter (F_FF(z)) based on the sound recorded by the outer microphone (M1) and the inner microphone (M2).

4. An earphone in particular as set forth in claim 1, comprising

a first side (L) having a first housing (LK) and/or a second side (R) having a second housing (RK) for respectively receiving an electroacoustic reproduction transducer (W), at least one outer microphone (M1) at the first and/or second housing (LK, RK) for recording outside sound,

at least one inner microphone (M2) at the first and/or second housing (LK, RK) for recording sound in the region between an ear of a user and the left and/or right housing (LK, RK) of the earphone, and

an active noise reduction unit (ANR) for performing active noise reduction based on the sound recorded by the at least one outer microphone and by the at least one inner microphone,

wherein the active noise reduction unit (ANR) is adapted to perform active noise reduction for the first side of the earphone based on the sound recorded by the outer microphone (M1L) at the first housing, by the inner microphone (M2L) at the first housing and by the outer microphone (M1R) at the second housing, and/or

wherein the active noise reduction unit (ANR) is adapted to perform active noise reduction for the second side of the earphone based on the sound recorded by the outer microphone (M1L) at the second housing, by the inner microphone (M2L) at the second housing and by the outer microphone (M1R) at the first housing.

5. An earphone as set forth in claim 4 wherein the active noise reduction unit (ANR) has a feedforward path with a first adaptive filter (F_FF(z)) and a filter adaptation unit (FAE) for ascertaining the filter parameters of the first filter (F_FF(z)) based on the sound recorded by the outer microphone (M1) and the inner microphone (M2).

6. An earphone, in particular as set forth in claim 1, comprising

at least one loudspeaker (W),

at least one outer microphone (M1) for recording outside sound,

at least one inner microphone (M2) for recording sound in the region of between an ear of a user and the earphone, and

an active noise reduction unit (ANR) for effecting active noise reduction based on the sound recorded by the at least one outer microphone and by the at least one inner microphone,

wherein the active noise reduction unit (ANR) has a feedforward path with a first adaptive filter (F_FF(z)), a filter adaptation unit (FAE) for ascertaining the filter parameters of the first filter (F_FF(z)) based on the sound recorded by the outer microphone (M1) and the inner microphone (M2), and an inner regulating circuit (IR),

wherein the inner regulating circuit (IR) has a first regulating unit (F_Str(z)) and a feedback regulating unit (F_FB(z)), wherein the output of the first regulating unit is coupled to the input of the feedback regulating unit, and wherein subtraction of the output of the feedback regulating unit from the output of the first adaptive filter (F_FF(z)) represents the input of the first regulating unit.

7. An earphone as set forth in claim 6 wherein the filter adaptation unit (FAE) has a model unit (F̂

_Str*(z)) for storing a mathematical model of the inner regulating circuit and for estimating the properties of the inner regulating circuit as well as an adaptation unit, wherein the adaptation unit is adapted to perform adapted filter parameters based on the sound recorded by the inner microphone and the output of the model unit in accordance with the least mean square method.

8. An earphone as set forth in claim 6 wherein the filter adaptation unit (FAE) has a first frequency-selective filter (HP) for frequency-elective filtering of the sound recorded by the outer microphone and a second frequency-selective filter (HP) for frequency-selective filtering of the sound recorded by the inner microphone.

9. An earphone comprising

an inner cap (IK) for bearing against an ear and an outer cap (AK) for enclosing an ear, wherein the inner cap has a loudspeaker (W) and an inner microphone (M2), and wherein an outer microphone (M1) for recording outside sound is arranged at the outer cap (AK), and

an active noise reduction unit (ANR) for performing active noise reduction based on the sound recorded by the at least one outer microphone and by the at least one inner microphone.

10. An earphone as set forth in claim 9 wherein the inner and outer caps are decoupled from each other.

11. A method of active noise reduction of an earphone having a first housing (LK, AK, IK) for receiving an electroacoustic reproduction transducer and a second housing (RK, AK, IK) for receiving an electroacoustic reproduction transducer, an outer microphone (M1) for recording outside sound and an inner microphone for recording sound in the region between an ear of a user and the first or second housing, comprising the steps:

performing active noise reduction based on the sound recorded by the outer microphone and by the inner microphone,

analyzing the sound recorded by the outer microphone and by the inner microphone,

determining the signal types of the recorded sound,

providing a plurality of signal processing units for respectively performing noise reduction for a signal type, and

selecting one of the signal processing units for performing noise reduction based on the implemented analysis of the recorded sound.