<!ELEMENT acoustic (measured_data)>
<!ELEMENT spl (metric, channel?, filter_response, sum_data*, band?)>
<!ELEMENT pwl (channel?, band?)>
<!ELEMENT vibration (metric, channel?, filter_response, sum_data*, band?)>
<!ELEMENT metric (#PCDATA)>
<!ELEMENT channel (#PCDATA)>
<!ELEMENT filter_response (#PCDATA)>
<!ELEMENT sum_data (#PCDATA)>
<!ELEMENT band (band_data+)>
<!ELEMENT measured_data (spl+|pwl+|vibration+)>
<!ELEMENT modeled_data (spl+|vibration+)>
<!ELEMENT band_data (#PCDATA)>
<!ATTLIST spl 
	time_unit CDATA #REQUIRED
	length CDATA #REQUIRED
	interval CDATA #IMPLIED>
<!ATTLIST vibration
	time_unit CDATA #REQUIRED
	length CDATA #REQUIRED
	interval CDATA #IMPLIED
	integration CDATA #REQUIRED>
<!ATTLIST sum_data
	weighting CDATA #REQUIRED
	ident CDATA #IMPLIED
	avg_time CDATA #REQUIRED>
<!ATTLIST band
	filter CDATA #REQUIRED
	division CDATA #REQUIRED
	avg_time CDATA #REQUIRED>
<!ATTLIST band_data
	centerfreq CDATA #REQUIRED
	weighting CDATA #IMPLIED>