Does Frisian converge towards Dutch? That question has often been asked and some evidence seems to support that idea. To study whether the sound system of Frisian was really changing towards Dutch, The Boarnsterhim Corpus (henceforth BHC) was recorded in 1982-1984. The studies that followed from this suggest that the Frisian sound system was stable. In some respects, the distinction between Frisian and Dutch became even stronger. To further investigate whether this trend continues, the BHC2 is recorded in 2017-2019. Recordings and analyses of four generations of speech provides the opportunity to investigate the stability, variation, and change of the Frisian sound system over 100 years.
In both periods, speakers of three generations of the same families were recorded: grandmother, mother, and daughter; or grandfather, father, and grandson. The two younger generations of the first period overlap with the oldest two generations of the second period. A unique property of this corpus is that as far as possible, half of the overlapping generations in the BHC1 and the BHC2 consists of speech of the same individuals.
All speakers were recorded twice. One time they were recorded in Frisian with a native interviewer to ensure informal Frisian speech. The other time they were recorded in Dutch with a monolingual Dutch interviewer to avoid Frisian. Each recording consists of 20 read sentences, a read story (2-3 minutes), and an interview of about 40 minutes about the speaker’s use of Frisian, language attitude, and daily life activities. In the BHC1, data were recorded on cassette tapes which were digitalized in 2016. The BHC2 is a replication of the BHC1, with the same number of speakers and same age groups.
With the assistance of research assistants, interns, and volunteers, the data are annotated in Praat speech processing software. This separates the phrases, words, and sounds (with an accuracy of milliseconds). There are separate tiers (levels) for:
- phonetic realization
- deletion of speech sounds
- specific phonological processes