The term 'murmured softly' can be expressed in two different ways: as 'soughed' (7 letters) or 'cooed' (5 letters). Both words refer to a low, gentle sound made by a person or animal, usually expressing contentment or pleasure. Soughed is an old-fashioned word that means to make a soft, murmuring sound, while cooed is a more modern term that means to make a low, gentle sound, often used to express affection.