Examine the following data from Spanish. Note that [β] represents a voiced bilabial fricative, and [É£] a voiced velar fricative. What is the purpose of using [β] and [É£] in the data?
1) To indicate the pronunciation of certain Spanish words
2) To represent the phonetic symbols used in Spanish language textbooks
3) To highlight the differences between voiced bilabial fricatives and voiced velar fricatives
4) To demonstrate the influence of other languages on the Spanish language