A vehicle door latch apparatus comprising: a latch unit that is attached to an end portion of a vehicle door, the latch unit including: a latch that has a half-latching step that defines a half-latched position, as well as a full-latching step that defines a full-latched position, and that is rotated from an unlatched position toward the full-latched position when the latch engages a striker, a ratchet that prevents the latch from rotating in an unlatching direction when the ratchet engages the half-latching step and the full-latching step, and a first cinching lever that is rotated to displace the latch from the half-latched position to the full-latched position, a cable that rotates the first cinching lever; and a power unit that is attached to the vehicle door and that is separated from the latch unit, the power unit including a motor, a cable drum onto which one end of the cable is wound and that takes up and feeds the cable, a deceleration mechanism that transfers power of the motor to the cable drum, and a closed-type housing that houses the motor, the cable drum and the deceleration mechanism, characterised in that; operation noise at 300mm right above the housing of the power unit is 42.2 to 40.9 dB at a supply voltage to the motor of 9V, 47.5 to 43.9 dB at a supply voltage of 12V, and 49.7 to 46.5 dB at a supply voltage of16 V, the deceleration mechanism includes a large-diameter gear and a small-diameter gear that are integrally formed and that are coaxial with each other, the motor has a cylindrical worm formed on an output shaft thereof, and the cable drum has a drum gear on an outer peripheral surface thereof, and the large-diameter gear is a worm wheel gear that engages the cylindrical worm, and the small-diameter gear is a helical gear that engages the drum gear. a latch unit that is attached to an end portion of a vehicle door, the latch unit including: a latch that has a half-latching step that defines a half-latched position, as well as a full-latching step that defines a full-latched position, and that is rotated from an unlatched position toward the full-latched position when the latch engages a striker, a ratchet that prevents the latch from rotating in an unlatching direction when the ratchet engages the half-latching step and the full-latching step, and a first cinching lever that is rotated to displace the latch from the half-latched position to the full-latched position, a latch that has a half-latching step that defines a half-latched position, as well as a full-latching step that defines a full-latched position, and that is rotated from an unlatched position toward the full-latched position when the latch engages a striker, a ratchet that prevents the latch from rotating in an unlatching direction when the ratchet engages the half-latching step and the full-latching step, and a first cinching lever that is rotated to displace the latch from the half-latched position to the full-latched position, a cable that rotates the first cinching lever; and a power unit that is attached to the vehicle door and that is separated from the latch unit, the power unit including a motor, a cable drum onto which one end of the cable is wound and that takes up and feeds the cable, a deceleration mechanism that transfers power of the motor to the cable drum, and a closed-type housing that houses the motor, the cable drum and the deceleration mechanism, characterised in that; operation noise at 300mm right above the housing of the power unit is 42.2 to 40.9 dB at a supply voltage to the motor of 9V, 47.5 to 43.9 dB at a supply voltage of 12V, and 49.7 to 46.5 dB at a supply voltage of16 V, the deceleration mechanism includes a large-diameter gear and a small-diameter gear that are integrally formed and that are coaxial with each other, the motor has a cylindrical worm formed on an output shaft thereof, and the cable drum has a drum gear on an outer peripheral surface thereof, and the large-diameter gear is a worm wheel gear that engages the cylindrical worm, and the small-diameter gear is a helical gear that engages the drum gear.