Final answer:
The intelligibility of speech is affected by the absence of frequencies above 600Hz because these frequencies contain important consonant sounds needed for clarity. Hearing loss in these higher frequencies, known as presbycusis, impacts speech recognition and appreciation of music.
Step-by-step explanation:
The absence of frequencies above 600Hz can adversely affect the intelligibility of speech. The human ear has a wide range of audible frequencies, generally considered to be from 20Hz to 20,000Hz.
Normal conversation falls within this range, with most conversational sounds occurring between 250Hz and 8000Hz. High-frequency sounds are important for understanding speech because they contain the consonant sounds of speech that give words their clarity.
Furthermore, hearing tests often reveal that hearing loss at higher frequencies, a condition known as presbycusis, can make it difficult to appreciate music and recognize speech, particularly the higher-pitched voices such as those of women.