Abstract: A hearing aid (100) comprises a body case (2) that is worn behind an ear (1), a sound conductor (3) that is linked at one end to the body case (2) and is linked at the other end to an earpiece (6), and an engaging component (8) for holding the earpiece linked to the other end of the sound conductor in the external auditory canal (7) of the ear (1). The engaging component (8) is made up of a first arc part (8a) disposed on the earpiece (6) side, a second arc part (8b) that is larger than the first arc part (8a) and is disposed opposite the first arc part (8a), a first linking part (8c) that links one end of the first arc part (8a) and one end of the second arc part (8b), and a second linking part (8d) that links the other end of the first arc part (8a) and the other end of the second arc part (8b). The second linking part (8d) has a shape such that its center part protrudes toward the first linking part (8c). This constitution allows the hearing aid (100) to be put on more easily.

Abstract: An arc-shaped waterproof wall is provided around a shaft to which a hearing aid main body case and a battery case are rotatably attached, and waterproof ribs are provided to the outer periphery of the installation face of the battery case and the hearing aid main body case, which improves the ability to prevent the penetration of moisture while also keep the cost low.

Abstract: A hearing aid (100) comprises a body case (2) that is worn behind an ear (1), a sound conductor (3) that is linked at one end to the body case (2) and is linked at the other end to an earpiece (6), and an engaging component (8) for holding the earpiece linked to the other end of the sound conductor in the external auditory canal (7) of the ear (1). The engaging component (8) is made up of a first arc part (8a) disposed on the earpiece (6) side, a second arc part (8b) that is larger than the first arc part (8a) and is disposed opposite the first arc part (8a), a first linking part (8c) that links one end of the first arc part (8a) and one end of the second arc part (8b), and a second linking part (8d) that links the other end of the first arc part (8a) and the other end of the second arc part (8b). The second linking part (8d) has a shape such that its center part protrudes toward the first linking part (8c). This constitution allows the hearing aid (100) to be put on more easily.

Abstract: A hearing aid includes a main body and a battery holder that can be opened and closed with respect to the main body by revolving around a revolving shaft. The main body has a lock bar provided so as to traverse the space in which the battery holder is installed, and a protruding portion that protrudes toward this installation space. The battery holder has a first concave portion and a second concave portion that latch the lock bar and the protruding portion.

Abstract: A hearing aid, wherein a front sound opening and a front microphone are acoustically connected via a front sound guide path, and the front sound guide path includes a first space formed between the front microphone and the electrical connection part inside the main body case, and a second space formed between the electrical connection part and the inner wall face of the main body case.

Abstract: A hearing aid, wherein a front sound opening and a front microphone are acoustically connected via a front sound guide path, and the front sound guide path includes a first space formed between the front microphone and the electrical connection part inside the main body case, and a second space formed between the electrical connection part and the inner wall face of the main body case.

Abstract: In a hearing aid, a main body case has a fitting-use first communication terminal provided inside the main body case, so that the first communication terminal can be visually checked when the battery case is removed by turning, and the battery case has a first locking protrusion that is engaged with the main body case and a pressing protrusion that is opposite the first communication terminal, when the battery case is turned for installation.

Abstract: An arc-shaped waterproof wall is provided around a shaft to which a hearing aid main body case and a battery case are rotatably attached, and waterproof ribs are provided to the outer periphery of the installation face of the battery case and the hearing aid main body case, which improves the ability to prevent the penetration of moisture while also keep the cost low.

Abstract: In a hearing aid, a main body case has a fitting-use first communication terminal provided inside the main body case, so that the first communication terminal can be visually checked when the battery case is removed by turning, and the battery case has a first locking protrusion that is engaged with the main body case and a pressing protrusion that is opposite the first communication terminal, when the battery case is turned for installation.

Abstract: A hearing aid (100) comprises a main body (10) and a battery holder (50) that can be opened and closed with respect to the main body by revolving around a revolving shaft. The main body (10) has a lock bar (12) provided so as to traverse the space in which the battery holder (50) is installed, and a protruding portion (14) that protrudes toward this installation space. The battery holder (50) has a first concave portion (62) and a second concave portion (64) that latch the lock bar and the protruding portion.