How did phonograms represent sounds in Egyptian hieroglyphic writing?

In Egyptian hieroglyphic writing, phonograms represent sounds rather than meanings. These signs are categorized based on the number of sounds they denote:

• Simple phonemes: These typically originated from logograms depicting specific objects but evolved to acquire a purely phonetic character.1
• Biliteral and triliteral signs: These represent a sequence of two or three consonant sounds, respectively.1

The system primarily records consonants, as Egyptian writing generally omitted vowels, with the exception of the semivowels i, y, and w. To clarify pronunciation, scribes often used the rebus principle—representing abstract words by using pictures of objects with similar sounds—or accompanied complex signs with simpler phonetic indicators as reading aids. Because these signs were often combined with logograms and determinatives to specify meaning, the hieroglyphic system provides an imperfect reflection of the language's actual pronunciation.12