A speaker comprises a housing, a transducer residing inside the housing, and at least one sound guiding hole located on the housing. The transducer generates vibrations. The vibrations produce a sound wave inside the housing and cause a leaked sound wave spreading outside the housing from a portion of the housing. The at least one sound guiding hole guides the sound wave inside the housing through the at least one sound guiding hole to an outside of the housing. The guided sound wave interferes with the leaked sound wave in a target region. The interference at a specific frequency relates to a distance between the at least one sound guiding hole and the portion of the housing.

A speaker comprises a housing, a transducer residing inside the housing, and at least one sound guiding hole located on the housing. The transducer generates vibrations. The vibrations produce a sound wave inside the housing and cause a leaked sound wave spreading outside the housing from a portion of the housing. The at least one sound guiding hole guides the sound wave inside the housing through the at least one sound guiding hole to an outside of the housing. The guided sound wave interferes with the leaked sound wave in a target region. The interference at a specific frequency relates to a distance between the at least one sound guiding hole and the portion of the housing.

A speaker comprises a housing, a transducer residing inside the housing, and at least one sound guiding hole located on the housing. The transducer generates vibrations. The vibrations produce a sound wave inside the housing and cause a leaked sound wave spreading outside the housing from a portion of the housing. The at least one sound guiding hole guides the sound wave inside the housing through the at least one sound guiding hole to an outside of the housing. The guided sound wave interferes with the leaked sound wave in a target region. The interference at a specific frequency relates to a distance between the at least one sound guiding hole and the portion of the housing.

A speaker comprises a housing, a transducer residing inside the housing, and at least one sound guiding hole located on the housing. The transducer generates vibrations. The vibrations produce a sound wave inside the housing and cause a leaked sound wave spreading outside the housing from a portion of the housing. The at least one sound guiding hole guides the sound wave inside the housing through the at least one sound guiding hole to an outside of the housing. The guided sound wave interferes with the leaked sound wave in a target region. The interference at a specific frequency relates to a distance between the at least one sound guiding hole and the portion of the housing.

A speaker comprises a housing, a transducer residing inside the housing, and at least one sound guiding hole located on the housing. The transducer generates vibrations. The vibrations produce a sound wave inside the housing and cause a leaked sound wave spreading outside the housing from a portion of the housing. The at least one sound guiding hole guides the sound wave inside the housing through the at least one sound guiding hole to an outside of the housing. The guided sound wave interferes with the leaked sound wave in a target region. The interference at a specific frequency relates to a distance between the at least one sound guiding hole and the portion of the housing.

A speaker comprises a housing, a transducer residing inside the housing, and at least one sound guiding hole located on the housing. The transducer generates vibrations. The vibrations produce a sound wave inside the housing and cause a leaked sound wave spreading outside the housing from a portion of the housing. The at least one sound guiding hole guides the sound wave inside the housing through the at least one sound guiding hole to an outside of the housing. The guided sound wave interferes with the leaked sound wave in a target region. The interference at a specific frequency relates to a distance between the at least one sound guiding hole and the portion of the housing.

A speaker comprises a housing, a transducer residing inside the housing, and at least one sound guiding hole located on the housing. The transducer generates vibrations. The vibrations produce a sound wave inside the housing and cause a leaked sound wave spreading outside the housing from a portion of the housing. The at least one sound guiding hole guides the sound wave inside the housing through the at least one sound guiding hole to an outside of the housing. The guided sound wave interferes with the leaked sound wave in a target region. The interference at a specific frequency relates to a distance between the at least one sound guiding hole and the portion of the housing.

Aspects of the disclosure provide a packaging technique for making a directional microphone which employs mechanical structures to cancel undesired background noise to realize the directional function instead of an extra sensor required in electronic noise-cancelling techniques, thus reducing footprint and cost of a directional microphone. A directional microphone based on this technique can include an acoustic sensor and a housing enclosing the acoustic sensor. The acoustic sensor can include a sensing diaphragm, a cavity below the sensing diaphragm, and a first substrate. The directional microphone device can further include a channel with an inlet open at an edge of the first substrate and an outlet connected with the cavity. The housing can include a cover attached to a second substrate supporting the first substrate. The cover can include a first opening over the sensing diaphragm and a second opening at a side of the cover.

A wearable speaker system includes a bellows tube that holds a weight inside, and a speaker unit where a space inside the speaker unit and a space inside the bellows tube communicate with each other. The bellows tube is accommodated in the enclosure, and both end portions of the bellows tube are fixed to the enclosure.

Disclosed is a lighting module (10) comprising a carrier (20) having a major surface (21) including a plurality of first regions (23) and a plurality of second regions (25), each second region being adjacent to a first region. The lighting module also has a plurality of light engines (40), each light engine being located in a first region of said carrier, and an optically transmissive light exit structure (50) facing the major surface and being spatially separated therefrom. Each first region is covered by a separate cover (30) that is optically transmissive and acoustically reflective. Each cover has a surface portion with a surface normal (31) under a non-zero angle () with the surface normal (51) of the light exit structure so that it is shaped to reflect sound waves (33) towards an adjacent second region (25). Each second region has an acoustically absorbent member (35) arranged to absorb said reflected sound waves. Also disclosed is a lighting kit (100) comprising a plurality of such lighting modules.