An acoustic band-pass filter assembly includes an inlet, a microphone configured to receive acoustic energy from the inlet, and a plurality of resonator chambers disposed in series between the inlet and the microphone and configured to transmit acoustic energy between the inlet and the microphone. Each of the plurality of resonator chambers has a different cross-sectional area.

Certain example embodiments relate to an acoustic wall assembly that uses active and/or passive sound reverberation to achieve noise-disruptive functionality, and/or a method of making and/or using the same. With the active approach, sound waves in a given frequency range are detected by a sound masking circuit. Responsive to detection of such sound waves, an air pump (e.g., speaker) is used to pump air in the wall assembly to actively mask the detected sound waves via reverberation and/or the like. The wall assembly may include one, two, or more walls, and the walls may be partial or full walls. With the passive approach, sound waves in a given frequency range are disrupted via features (e.g., holes, slits, etc.) formed in and/or on a wall itself. These techniques may be used together or separately, in different example embodiments.

Certain example embodiments relate to an acoustic wall assembly that uses active and/or passive sound reverberation to achieve noise-disruptive functionality, and/or a method of making and/or using the same. With the active approach, sound waves in a given frequency range are detected by a sound masking circuit. Responsive to detection of such sound waves, an air pump (e.g., speaker) is used to pump air in the wall assembly to actively mask the detected sound waves via reverberation and/or the like. The wall assembly may include one, two, or more walls, and the walls may be partial or full walls. With the passive approach, sound waves in a given frequency range are disrupted via features (e.g., holes, slits, etc.) formed in and/or on a wall itself. These techniques may be used together or separately, in different example embodiments.

Described are methods and systems for broad-band active reduction of noise in target spaces, such as spaces around headrests in aircraft cabins. Systems describe herein are effective over wide frequency ranges without causing undesirable amplification at any subrange ranges. Specifically, a system comprises a speaker and a resonator, both coupled to an enclosure. The interior space of the resonator is in fluid communication with the enclosed space of the enclosure, allowing the resonator to reduce the amplitude of unwanted amplification by the audio reducing sound generated by the speaker. The amplitude is reduced in a selected frequency range, which may correspond to an expected amplification for this particular system. The resonator may partially extend into the enclosure or may be completely incorporated into the enclosure. Some examples of the resonator include a Helmholtz resonator, a passive radiator, a quarter wave resonator, a pipe resonator, and an acoustic metamaterial.

Described are methods and systems for broad-band active reduction of noise in target spaces, such as spaces around headrests in aircraft cabins. Systems describe herein are effective over wide frequency ranges without causing undesirable amplification at any subrange ranges. Specifically, a system comprises a speaker and a resonator, both coupled to an enclosure. The interior space of the resonator is in fluid communication with the enclosed space of the enclosure, allowing the resonator to reduce the amplitude of unwanted amplification by the audio reducing sound generated by the speaker. The amplitude is reduced in a selected frequency range, which may correspond to an expected amplification for this particular system. The resonator may partially extend into the enclosure or may be completely incorporated into the enclosure. Some examples of the resonator include a Helmholtz resonator, a passive radiator, a quarter wave resonator, a pipe resonator, and an acoustic metamaterial.

Described are methods and systems for broad-band active reduction of noise in target spaces, such as spaces around headrests in aircraft cabins. Systems describe herein are effective over wide frequency ranges without causing undesirable amplification at any subrange ranges. Specifically, a system comprises a speaker and a resonator, both coupled to an enclosure. The interior space of the resonator is in fluid communication with the enclosed space of the enclosure, allowing the resonator to reduce the amplitude of unwanted amplification by the audio reducing sound generated by the speaker. The amplitude is reduced in a selected frequency range, which may correspond to an expected amplification for this particular system. The resonator may partially extend into the enclosure or may be completely incorporated into the enclosure. Some examples of the resonator include a Helmholtz resonator, a passive radiator, a quarter wave resonator, a pipe resonator, and an acoustic metamaterial.

Certain example embodiments relate to an acoustic wall assembly that uses active and/or passive sound reverberation to achieve noise-disruptive functionality, and/or a method of making and/or using the same. With the active approach, sound waves in a given frequency range are detected by a sound masking circuit. Responsive to detection of such sound waves, an air pump (e.g., speaker) is used to pump air in the wall assembly to actively mask the detected sound waves via reverberation and/or the like. The wall assembly may include one, two, or more walls, and the walls may be partial or full walls. With the passive approach, sound waves in a given frequency range are disrupted via features (e.g., holes, slits, etc.) formed in and/or on a wall itself. These techniques may be used together or separately, in different example embodiments.

Wearable devices may include a housing including a first surface facing a first direction and having a speaker nozzle part, and a second surface facing a second direction opposite to the first direction and having at least one microphone hole. A speaker and a microphone are disposed in the housing, the microphone configured to collect an acoustic signal. A partition wall is positioned between the speaker and the microphone. A first space is defined between the speaker and the partition wall, a first path is provided for connecting the speaker and the speaker nozzle part, and a second path, separated from the first space by the partition wall, connects the microphone and the first path.