The word(s) "murmur" appears 3 time(s) in 3 verse(s) in Quran in Muhammad Pickthal translation.

(1) murmuring among themselves: Ye have tarried but ten (days).

(سورة طه, Taa-Haa, Chapter #20, Verse #103)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)

(2) On that day they follow the summoner who deceiveth not, and voices are hushed for the Beneficent, and thou hearest but a faint murmur.

(سورة طه, Taa-Haa, Chapter #20, Verse #108)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)

(3) Had it not been for the grace of Allah and His mercy unto you in the world and the Hereafter an awful doom had overtaken you for that whereof ye murmured.

(سورة النور, An-Noor, Chapter #24, Verse #14)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)