The primary aim of this database is to provide users with an easy way to hear or download natural language example of specified sounds. At the moment it searches for sounds sounds in the IPA Illustrations of Languages files and in the UCLA Phonetics Lab Data. Note that the UCLA Phonetics Lab Data includes a number of sounds (e.g. the contrasting phonation types in Bruu and Mpi and the different degrees of retroflexion in Badaga) that cannot be found using this search engine because there are no approved ways of symbolizing these contrasts in IPA terms.
A second possible use for the database is investigating phonological systems to find languages that have, or do not have, certain contrasts. This can be done only when restricting the search to IPA Language Illustrations , and even then only with care. The UCLA Phonetic Lab Data is intended just to provide examples of sounds. A search in this source for a language that contains [p] but not [b], for example, may produce an erroneous result as it will find languages that actually have both sounds but only one of them is listed in the UCLA section of the database. Using the IPA Language Illustrations data source may also produce erroneous results in another way, as some of these Illustrations include allophones. It is always advisable to check the phonological systems as listed in the original papers in the Journal of the International Phonetic Association, or in the Handbook of the IPA .
Note that there are inevitably possibilities for confusion because of the various sources for the data. A voiceless bilabial plosive unspecified for aspiration will have been labeled "p" in the database, and a bilabial plosive with aspiration specified will have been entered as "ph". But the data may contain bilabial plosives that are aspirated without the aspiration having been explicitly marked. Remember that the International Phonetic Alphabet (the IPA) is designed to allow different kinds of transcriptions. Users may make detailed specifications of sounds in a narrow phonetic transcription with diacritics; alternatively they may show just contrasting sounds using the simplest possible symbols in a broad phonemic transcription. Some contributions to these databases use one style, others the other. Both are equally valid IPA transcriptions.