Both the WAVE and AIFF modules embed audio metadata in AES format without providing a schema. One of the produced element make use of xsi:type, <tcf:filmFraming tcf:framing="NOT_APPLICABLE" xsi:type="tcf:ntscFilmFramingType"/>. Because JHOVE schema does not validate embedded xml (processContents="skip"), the use of xsi:type does not cause problem. However, METS & PREMIS schema will validate embedded xml if sufficient definition is available (processContents="lax"). When we import this element into PREMIS document, it is not valid because xsi:type references a Type Definition(http://www.w3.org/TR/xmlschema-1/#xsi_type), thus explicit assertion of type validation is attempted. The type tcf:ntscFilmFramingType cannot be resolved and causes validation to fail.
Looking into aes.org, we cannot find a schema describing the element in the namespace http://www.aes.org/tcf. It appears the AES X098B schema is not publicly available yet (according to Gary).