Learn Farsi: یک گوش شنوا این صوت را راحت خواهد شنید. - A hearing ear will easily hear this sound.

This suffix attaches to the present stem of a verb to form an inherent state adjective—a word describing someone or something that constantly has that trait or ability. The verb شنیدن (to hear) has the present stem شنو (šenav). Adding -ا gives us شنوا (šenavâ), meaning 'capable of hearing' or, as translated here, 'hearing'.

Why does this sentence use صوت (sowt) for 'sound' instead of the more common صدا (sedâ)?

While صدا is the everyday word for sound or voice, صوت is a slightly more formal, literary, or technical term for 'sound'. Because this sentence has a somewhat poetic or proverb-like tone ('A hearing ear...'), صوت fits the register perfectly.

راحت (râhat) usually means 'comfortable.' Why does it translate to 'easily' here?

In Farsi, adjectives are frequently used as adverbs without needing any extra suffixes (like '-ly' in English). Since راحت is directly modifying the verb خواهد شنید (will hear), it acts as an adverb meaning 'comfortably' or 'easily'.

Is the formal future tense خواهد شنید (xâhad šenid) common in everyday conversation?

No, in spoken Farsi, people rarely use this formal future structure (خواهد + short infinitive). Instead, they typically use the simple present or present continuous (like می‌شنود) for future events. The use of خواهد شنید here reinforces the sentence's formal, written register.