The U.S. aircraft register, updated daily
Who holds what · as the FAA records the name

Sennheiser Electronic GMBH & Co.Kg.

Named as the FAA publishes it on its approvals.

Approved to make 3 classes of equipment. FAA spelling: Sennheiser Electronic GmbH & Co.Kg..

Equipment approvals technical standard order authorisations

2013-11-14TSO-C139 · Aircraft Audio Systems and Equipment · Headset, Headphone, Headsets and Headphones · other and general
TSO-C58A · Aircraft Microphones (Except Carbon) · *, *, * · other and general
TSO-C57A · Headsets And Speakers · *, *, * · other and general

Source: FAA Dynamic Regulatory System (type certificate data sheets, supplemental type certificates, parts manufacturer approvals, technical standard order authorisations). An organisation's name is as the FAA spelled it on each record; related spellings are separate pages.