MAUDE Adverse Event Report: Cochlear Ltd Nucleus CI522 Cochlear Implant with Slim Straight Electrode; Nucleus 24 Cochlear Implant System

Model Number	CI522
Medical Device Problem Codes	Signal Artifact/Noise (1036); Therapeutic or Diagnostic Output Failure (3023)
Health Effect - Clinical Code	Appropriate Clinical Signs, Symptoms and Conditions Term/Code Not Available (4581)
Date of Event	08/18/2026
Type of Reportable Event	Serious Injury
Event or Problem Description
Per the clinic, the patient reported a sudden onset of screeching sound quality in (b)(6) 2025 while wearing the external processor.The patient was prescribed with prophylactic antibiotics and programming adjustments were made, after which the patient was able to wear the processor intermittently between (b)(6) 2025.In (b)(6) 2026, the patient returned to the clinic reporting recurrence of the screeching sound and stopped wearing the external processor.It was also noted that, the patient experienced performance decrement with the device.Subsequently, the device was explanted on (b)(6) 2026.It is unknown if there are plans to reimplant the patient as of the date of this report.

• Brand Name: Nucleus CI522 Cochlear Implant with Slim Straight Electrode
• Common Device Name: Nucleus 24 Cochlear Implant System
• Manufacturer (Section D): Cochlear Ltd; 1 university avenue; macquarie university, nsw 2109 ; AS 2109
• Manufacturer (Section G): Cochlear Ltd; 1 university avenue; macquarie university, nsw 2109 ; AS 2109
• Manufacturer Contact: hemavathi muniesparan ; unit ug-1, vertical podium; no.8 jalan kerinchi; kuala lumpur, wilayah persekutuan 59200 ; MY 59200
• MDR Report Key: 50928049
• Report Number: 6000034-2026-03447
• Device Sequence Number: 10749632
• Product Code: MCM
• UDI-Device Identifier: 09321502032599
• Combination Product (Y/N): N
• Initial Reporter State: MO
• Initial Reporter Country: US
• PMA/510(K) Number: P970051
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2019
• Device Explanted Year: 2026
• Serviced by Third Party (Y/N): N
• Reporter Type: Manufacturer
• Report Source: Health Professional
• Type of Report: Initial
• Report Date (Section B): 09/29/2026

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: No
• Operator of Device: Lay User/Patient
• Device Expiration Date: 04/17/2021
• Device Model Number: CI522
• Device Catalogue Number: Z382660
• Was Device Available for Evaluation?: Yes
• Date Returned to Manufacturer: 09/02/2026
• Is the Reporter a Health Professional?: No
• Initial Date Received by Manufacturer: 09/07/2026
• Initial Report FDA Received Date: 09/29/2026
• Was Device Evaluated by Manufacturer? (Y/N): No
• Date Device Manufactured: 04/18/2019
• Is the Device Labeled for Single Use? (Y/N): Yes
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Usage of Device: Initial
• Patient Sequence Number: 1
• Outcome Attributed to Adverse Event: Required Intervention
• Patient Sex: Female