Only in Mirkwood do we find the word ruffle – once as the sound of feet among the leaves (as in ruffles and flourishes) and once as in disturbed smoothness – within five paragraphs of one another.

• 08.037 Their feet ruffled
• 08.042 ruffled here and there by the breeze;

“ruffle, n.4.” OED Online. Oxford University Press, March 2015. Web. 29 May 2015.

“ruffle, v.1.” OED Online. Oxford University Press, March 2015. Web. 29 May 2015.

“ruffle, v.3.” OED Online. Oxford University Press, March 2015. Web. 29 May 2015.

The last roaring is part of a magnificent image of Beorn:

The roar of his voice was like drums and guns; and he tossed wolves and goblins from his path like straws and feathers. He fell upon their rear, and broke like a clap of thunder through the ring.

• 01.079 The pines were roaring on the height,
• 07.099 and like a tide it roared and rolled;
• 10.006 like a distant roar.
• 12.021 roaring like thunder underground,
• 12.029 with a noise like a roaring wind.
• 12.031 they could hear the roar of the flying dragon grow
• 12.101 they heard the roar
• 14.011 before the roar of Smaug’s terrible approach grew loud,
• 14.013 Roaring he swept back over the town.
• 14.024 The lake roared in.
• 17.040 Winter thunder on a wild wind rolled roaring up
• 17.051 there rose from across the valley a deep-throated roar.
• 18.023 The roar of his voice was like drums

All of these rattling sounds seem to threaten.

• 05.143 swords rattled,
• 06.040 in a fearful confusion of slipping, rattling, cracking slabs
• 07.101 the reeds were rattling – on it went
• 13.058 and he rattled the precious stones
• 14.013 and rattled on his scales