Ok, thank you very much for your diagnostic confirmation It's strange because the audiomoth is supposed to be new... gpau

Yes, recording my voice at approx. 40 cm is what I did for the tests (including the sonogram above) I bought this audiomoth here: https://www.ebay.fr/itm/235688142124?_nkw=audiomoth&itmmeta=01J5B4093BMW32BT5KSSJSJWCG&hash=item36e01ba52c:g:OpUAAOSw9DRmnOkm&itmprp=enc%3AAQAJAAAAwHoV3kP08IDx%2BKZ9MfhVJKmMWYgNIZsIEvWI%2BgyViRXOtygk5Kc2B7zKbhwvwdQ0b4UIhOgKK%2FcQ2T5ZyT%2BZ9KHqqXQxzAiOviRd59E0GqiRkBhsmkX2VUPjtm4VOtJo682FN0R%2BFpfl3Zl5uintuXOKCmrKPn3NGvsR9Ei8b7BCO1C5SYVhTxUBcVl2rmPG6qJtOCcPwGBKMbZcGr%2BYClCH1cRIz9uQE6A2lNyzLqaXv3VXYdE5%2BSYQumezueSs8g%3D%3D%7Ctkp%3ABk9SR-KRgeSqZA