ACTIVE SOUND REDUCTION SYSTEM AND METHOD

• US 20120163626A1
• Filed: 07/30/2010
• Published: 06/28/2012
• Est. Priority Date: 08/07/2009
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Van Leest, Adriaan Johan, Aarts, Ronaldus Maria, Booij, Paul Sebastian
• Granted Patent: US 9,384,727 B2
• Time in Patent Office: Days
• US Class Current: 381/92
• 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 11/17881 the reference signal being an acoustic signal, e.g. recorded with a microphone

Abstract

The present invention refers to an active sound reduction system and method for attenuation of sound emitted by a primary sound source, especially for attenuation of snoring sounds emitted by a human being. This system comprises a primary sound source, at least one speaker as a secondary sound source for producing an attenuating sound to be superposed with the sound emitted by said primary sound source, a reference microphone for receiving sound from said primary sound source, and at least one error microphone being allocated to each speaker to form a speaker/microphone pair. The at least one error microphone is provided as a directional microphone pointing at its allocated speaker to receive residual sound resulting from the superposition of the sounds from the primary sound source and the corresponding speaker. The error microphone and speaker of at least one speaker/microphone pair and the primary sound source are arranged substantially collinear. A control unit is provided to receive an output reference signal of the reference microphone representing the sound received by the reference microphone and an output error signal of the at least one error microphone representing the sound received by the at least one error microphone and to calculate a control signal for the speaker from the output reference signal and the output error signal.

Claims

1. Active sound reduction system (10,50) for attenuation of sound emitted by a primary sound source, especially for attenuation of snoring sounds emitted by a human being,

comprising a primary sound source (12),

at least one speaker (24,64,66,68) as a secondary sound source for producing an attenuating sound to be superposed with the sound emitted by said primary sound source (12),

a reference microphone (28) for receiving sound from said primary sound source (12),

at least one error microphone (34,58,60,62) being allocated to each speaker (24,64,66,68) to form a speaker/microphone pair (42,52,54,56), said at least one error microphone (34,58,60,62) being provided as a directional microphone pointing at its allocated speaker (24,64,66,68) to receive residual sound resulting from the superposition of the sounds from the primary sound source (12) and the corresponding speaker (24,64,66,68),

the error microphone (34,58,60,62) and speaker (24,64,66,68) of at least one speaker/microphone pair (42,52,54,56) and the primary sound source (12) being arranged substantially collinear,

and a control unit (32) for controlling said at least one speaker (24,64,66,68), said control unit (32) being provided to receive an output reference signal of the reference microphone (28) representing the sound received by the reference microphone (28) and an output error signal of the at least one error microphone (34,58,60,62) representing the sound received by the at least one error microphone (34,58,60,62) and to calculate a control signal from the output reference signal and the output error signal.

2. Active sound reduction system according to claim 1, wherein said primary sound source (12) is located between the error microphone (34,58,60,62) and the speaker (24,64,66,68) of the speaker/microphone pair (42,52,54,56) which is arranged substantially collinear with said primary sound source (12).

3. Active sound reduction system according to claim 1, comprising a number of error microphones (34,58,60,62) grouped together within an area in which the primary sound source (12) is located,

further comprising a number of speakers (24,64,66,68) being arranged around said area to form speaker/microphone pairs (42,52,54,56) together with said error microphones (34,58,60,62).

4. Active sound reduction system according to claim 3, wherein said area represented by the lying surface (16) of a bed (14), the error microphones (34,58,60,62) being grouped on or above said lying surface (16), their corresponding speakers (24,64,66,68) being arranged at the edge portions of the bed (14).

5. Active sound reduction system according to claim 4, comprising four error microphones (34,58,60,62) and four speakers (24,64,66,68) arranged at four different sides of said bed (14).

6. Active sound reduction system according to claim 3, wherein said error microphones (34,58,60,62) are integrated in a pillow.

7. Active sound reduction system according to claim 1, comprising at least one sound source to provide an additional masking sound for masking the sound emitted by said primary sound source (12).

8. Active sound reduction system according to claim 1, wherein said controller unit (32) is provided to identify a predictable portion of the output reference signal and to produce a control signal corresponding to said predictable portion.

9. Active sound reduction method for attenuating sound emitted by a primary sound source (12),

comprising the following steps:

providing at least one speaker (24,64,66,68) as a secondary sound source for producing an attenuating sound to be superposed with the sound emitted by said primary sound source (12),

allocating at least one error microphone (34,58,60,62) to each speaker (24,64,66,68) to form a speaker/microphone pair (42,52,54,56), said at least one error microphone (34,58,60,62) being provided as a directional microphone pointing at its allocated speaker (24,64,66,68) for receiving residual sound resulting from the superposition of the sounds from the primary sound source (12) and the speaker (24,64,66,68),

arranging the at least one error microphone (34,58,60,62) and the speaker (24,64,66,68) of at least one speaker/microphone pair (42,52,54,56) substantially collinear with said primary sound source (12),

receiving sound from said primary sound source (12) as a reference sound,

calculating a control signal from an output reference signal corresponding to the reference sound and from an output error signal corresponding to the residual sound,

controlling the speaker (24,64,66,68) by means of the control signal.

10. Active sound reduction method according to claim 9,

comprising arranging said primary sound source (12) between the error microphone (34,58,60,62) and the speaker (24,64,66,68) of said speaker/microphone pair (42,52,54,56) arranged substantially collinear with said primary sound source (12).

11. Active sound reduction method according to claim 9, comprising grouping a number of error microphones (34,58,60,62) within an area in which the primary sound source (12) is located,

and arranging the speakers (24,64,66,68) allocated to said error microphones (34,58,60,62) around said area.

12. Active sound reduction method according to claim 11, comprising grouping a number of error microphones (34,58,60,62) on or above the lying surface (16) of a bed (14) and arranging the speakers (24,64,66,68) at the edge portions of the bed (14).

13. Active sound reduction method according to claim 12, comprising four error microphones (34,58,60,62) arranged on or above the lying surface (16) of the bed (14) and four speakers (24,64,66,68) arranged at four different sides of said bed (14).

14. Active sound reduction method according to claim 9 comprising identifying a predictable portion of the output reference signal and to produce a control signal corresponding to said predictable portion.

15. Active sound reduction method according to claim 9 comprising producing an additional masking sound for masking the sound emitted by said primary sound source (12).