These stanzas from "Night Shift" by Sylvia Plath are replete with poetic devices and with sensory imagery, in particular. They describe a factory which is in full production, so naturally the descriptions are rich with the sights, sounds, and textures of a working factory.
The sound imagery is overwhelming: a "muted boom," a clangor, blood "drumming" in one's ears, noise, "metal detonating," the ground shaking with the pounding of the machinery, "thudding," turning wheels, the "[t]onnage of metal and wood" continually rising and falling. Just as effective is the imagery noting the absence of sounds, as a heart not beating, the "stilled suburbs," and the immense hammers which are raised but have not yet dropped.
The sight imagery is a contrast between the elements of the factory (metal, wood, grease) and the "stilled suburbs" in which the factory is set. The smell imagery is limited (perhaps the smells associated with the greenery of a neighborhood and the greased machinery), but the touch imagery is significant. Each of the components of the factory has a unique texture, such as the smooth coldness (or perhaps heat) of a metal pipe or the cogs of a machine's wheel. We also feel the shaking ground as tons of metal and wood are raised and dropped in a rhythmical pattern so characteristic of giant, powerful machinery.
On another level, the activity and sounds of the factory are compared, in a metaphor, with the beating of a human heart. In contrast to the slow, steady, rhythmical, muted beat of a human heart, the factory (though also moving with some regularity) is noisy, pounding, and clangorous.
The factory is personified (a non-human thing given human life or characteristics) when the speaker describes it as being "native" to the neighborhood and as "imposing" on its neighbors when the clamorous noises of the factory are felt in the neighborhood.
In terms of poetic devices, the fact that the pounding of the factory's machines is strong enough to shake the ground yet no one in the neighborhood reacts in the least to the shuddering earth. (Perhaps the people would not get up and scream at the factory as they might a neighbor's barking dog, but if it were true, surely no one would live long next to such a maddening occurrence every night.)
Examples of alliteration (repetition of initial consonant sounds) include this one:
These stilled suburbs nobody
Startled at it, though the sound
Shook the ground with its pounding.
Consonance (notice the sound rather than the appearance of consonant sounds) is evident in this stanza, as well:
Till the thudding source, exposed,
confounded in wept guesswork:
Framed in windows of Main Street’s
Silver factory, immense
"Boom" is a clear example of onomatopoeia (words that sound like what they mean), and "drumming," "shook," and "thudding" could also be considered onomatopoetic.
Finally, Plath uses enjambment, breaking a line in an unnatural place, most notably in the following lines:
Native, evidently, to
These stilled suburbs nobody
The first line (ending in "to") is the last line of one stanza; "These" begins another stanza. Enjambment is a poetic device used to interrupt the rhythm of the work or perhaps delay a thought. An effective reading of these lines will keep the poem from drifting into a too-patterned (even "sing-song") rhythm.
Clearly Plath wanted to overwhelm her readers with the clanging noise of a working factory in the midst of a quiet suburb.