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If you haven't already, please read my original proposal for an acoustic data format.

I made a first cut at constructing a DTD for my proposed XML acoustical data format.

You can download the DTD here. You can find two sample XML files based on this DTD here and here. (These files are based on comma delimited file from a Larson Davis Model 2900 RTA, available here and a SYLK file from a Rion Model NA-27 SLM available here. I've also set up a discussion forum specifically for this effort. If you have any comments/questions/criticisms/suggestions, please feel free to post there. Note that not everything that appears in the original files appears in the XML converted files, I just used enough data to convince myself that it works.

Internet Explorer 5.0 for the Mac OS and Internet Explorer 5.0/5.5 for WinXX allow you to view XML files in its hierarchy. You can also download a validator for the Windows version of IE 5 from Microsoft.

My spec for the DTD (please note this is a work in progress!):
acoustictop level element
 children:spl, pwl, phase, vibration
 
measured_data:data from a measurement instrument (SLM, RTA, etc)
 children:spl, pwl, phase, vibration
 
modeled_data:data from a noise model
 children:spl, pwl, phase, vibration
 
spl:element for descibing sound pressure data
 children:metric, channel filter_response, sum_data, band
 attributes:time_unit: spl data can be split into time slices time_unit is used to define the time unit for this time slices, typically seconds, minutes, hours, days, etc
  length: length of time slice, should be an integer value in units defined in "time_unit" attribute
  interval: numerical value identifing the number for consecutive time slices, integer value
 
pwl:acoustic power level (still a work in progress)
 children:channel, band
 
vibration:element for describing vibration data
 children:metric, channel, filter_response, sum_data, band
 attributes: time_unit: spl data can be split into time slices time_unit is used to define the time unit for this time slices, typically seconds, minutes, hours, days, etc
  length: length of time slice, should be an integer value in units defined in "time_unit" attribute
   interval: numerical value identifing the number for consecutive time slices, integer value
   integration: defines type of vibration data typical values: acceleration, velocity, displacement
 
metric:for spl & vibration, used to descibe specific type of data. Typical choices: Leq, Lmax, Lmin, L10/L50/L90/etc, Ldn
 
channel:for multi-channel equipment, specifies channel
 
filter_response:descibes electrical response of analyzer (note: this is not the same as frequency weighting). Typical choices: Exponential, Linear Repeat, Linear Single.
 
sum_data:placemarker for summed data (as opposed to spectral data)
 attributes:weighting: A-, B-, C-, D- weighting, or none
  ident:field for identifying sum_data. For example, an analyzer (such as the Rion NA-27) may record data on a main channel, and on a subchannel simultaneously. This attribute can be used to differentiate between these two channels
  avg_time:averaging time (in units of "time_unit" defined above) for the summed data
 
band:placemarker for spectral data
 children:band_data
 attributes: filter: identify octave band or narrow band
  division: for octave band filter, value should be 1/n where n is an integer, for narrow band, value should be delta Freq
   avg_time: averaging time (in units of "time_unit" defined above) for the spectral data
 
band_data:tags for spectral data values
 attributes: centerfreq: 1/n octave band or narrow band center frequency
  weighting: I haven't really decided on this one... it could be used for A-, B-, C-, D- weighting, or none.
 
Still to come:
insertion loss (for noise/vibration mitigation)
speaker modeling inputs (Theil/Small variables, etc)
tags to encapsulate binary data (WAV's, mp3's, etc)
May 14, 2000