Duration of the mandate and term of office of the lead auditor

At the Annual General Meeting on June 15, 2022, Ernst & Young AG, Zurich, was re-elected as auditor for Sonova Holding AG and the Sonova Group for the 2022/23 financial year. Martin Mattes has served as lead auditor for the auditing mandate.


The auditors charged the following fees during FY 2022/23 and 2021/22:



Ernst & Young


Ernst & Young

1,000 CHF





Audit services





Audit-related services





Tax services





Other non-audit services










Audit services are defined as the standard audit work performed each year in order to issue an audit opinion on the parent company and consolidated financial statements of the Sonova Group, as well as opinions on the local statutory financial accounts or statements. Also included is extra work within the audit that can only be provided by the Sonova Group auditor, such as auditing of non-recurring transactions or the implementation of new accounting policies, as well as consents and comfort letters in relation to regulatory filings.

Audit-related services consist of support to the audit, such as providing advice on new accounting rules; this could be provided by sources other than the auditor who signs the audit report.

Tax services consist of services in connection with compliance with tax laws.

Other non-audit services mainly consisted of development services rendered by Digital Detox Ventures Limited, a third party company unrelated to Sonova. Due to the acquisition of the said company by an Ernst & Young affiliate, Sonova has to disclose all fees paid subsequent to the effective date of the acquisition (August 1, 2022). This led to a significant increase in the disclosed fees for non-audit services. In order to continue to ensure Ernst & Youngʼs independence as Auditors while at the same time trying to minimize the impact on the timeline of Sonovaʼs project, Sonova swiftly initiated the mutual termination of the development agreement with effect still during the FY 2022/23, avoiding any spillover to the FY 2023/24.

The values of audit, audit-related, tax, and non-audit services are in line with ratios suggested by commonly applied good practice standards that relate to the independence of auditors. A formal policy issued by the Audit Committee is in place that regulates all non-audit assignments of the auditors.

Informational instruments pertaining to the external audit

The external auditors report their findings semi-annually directly to the Audit Committee of the Board of Directors. In FY 2022/23, the external auditors attended 3 out of 4 Audit Committee meetings physically or by telephone conference. The Audit Committee of the Board of Directors reviews the performance, compensation, and independence of the external auditors on a regular basis. The Audit Committee reports its findings to the Board of Directors on a quarterly basis.