344 - Sound Characteristics

 The 344 tag contains, per BF&S, "Technical specifications relating to the encoding of sound or the absence of sound in a resource." This can be useful when copy cataloging because it gives you a quick way to eliminate bibliographic records that are for different types of recordings than the one you have in hand.

This tag is repeatable, as are the various subfields. The preferred approach when cataloging this information, which is different from many other tags, is to use a separate subfield for each unique term.

For example, a record for a DVD might include these tags:

300    1 videodisc (118 min.) : ǂb sound, color ; ǂc 4 3/4 in
344    digital ǂ2 rdatr
344    ǂb optical ǂ2 rdarm
344    ǂg surround ǂ2 rdacpc
344    ǂg mono ǂ2 rdacpc
344    ǂh Dolby Digital 2.0
344    ǂh Dolby Digital 1.0

The 344 tag can include subfield 3 which is a control subfield and contains "an indication of the part of the described material to which the field applies. Subfield ǂ3 appears at the beginning of the field in cases where it is intended for display, otherwise it appears with other control subfields grouped at the end of the field." Basically this tells you which part of the thing the term applies to. Consider for example a multi-disc set of a concert which has both a film of the concert on DVD and a CD recording of it. Subfield 3 allows you to sort out what term goes with which disc.

There are quite a few subfields defined for the 344 tag, and many of them have an RDA term list which governs what can go there. These are the subfields I think are most likely to be useful for matching up records when copy cataloging:

• ǂa - type of recording - analog or digital are the options
  
  
• ǂb - recording medium - optical, magneto-optical, or magnetic -- not really very useful for matching, but I include it because it was part of the DVD example above
  
  
• ǂc - playing speed - 78rpm, 45rpm, etc. -- if you have a CD in hand and this subfield is present then that is not the record you are looking for
  
  
• ǂg - configuration of playback channels - mono, stereo, quadraphonic, or surround -- DVDs in particular often have several of these options included on them (indicated on the packaging) which can be useful information for selecting the correct record from a bunch of potential matches
  
  
• ǂh - special playback characteristics -- RDA defines a bunch of these -- useful for matching to the language of the packaging on your item in hand -- there could be multiple options included on a single disc and the correct matching record should list all of them
  
  
• ǂi - sound content -- "Indication of the presence or absence of sound in a resource" -- sound or silent are the options 

If you want to do a deep-dive into how sound characteristics are cataloged check out the Music Library Association's Best Practices and the OLAC Best Practices for Cataloging DVD-Video and Blu-Ray Discs.