Here's a challenge for you: try talking without sound. It's pretty hard to do, right? By the same token, it's hard to talk about speech without also discussing sound. With all the tongues flying around this poem, then, you know that you're in for some serious sound effects.
Let's start off with the more conventional sonic techniques that Bhatt uses here. For starters, check out lines 31-33:
it grows back, a stump of a shoot
grows longer, grows moist, grows strong veins,
it ties the other tongue in knots,
Take a second to read those lines out loud. Now, tell us that it didn't sound like a basket of snakes, slithering around inside your mouth. Poetically speaking, that's a technique called consonance. All those repeated S sounds ("grows," "stump," "moist," "strong," "veins," etc.) have the neat effect of re-enacting the metaphorical kind of plant growth being described here. We imagine a sinewy, slender vine that shoots forth as it grows bigger and bigger.
We also get a technique called anaphora: "the bud opens, the bud opens in my mouth" (34). The repetition of "the bud opens" in this line emphasizes the flourishing that's being described here. This is a flowering plant, one that reflects the speaker's renewed use of her native tongue. It only makes sense to see this repetition, then, because it reflects the speaker's excitement at this new growth. It also introduces a subtle sign of plentitude, as if we're not just dealing with one bud, but many.
Of course, the real sonic fireworks in this poem live in stanza 2. You don't think Bhatt's going to cold drop some Gujrati right into the middle of your English poem? Think again, gang. Not only does she include the native writing, but she wants to make sure that all you English speakers can pronounce those words as well.
The result is a kind of forced disruption that happens, crucially, as much on a sonic level as it does on a writing level. Thanks to those pronouncers, we're able to actually put the Gujrati words in our English-speaking mouths to see just what it feels like to have two "tongues" living side by side in there.
Appropriately enough, then, a poem called "Search for My Tongue" gives us plenty of opportunities to discover our own tongues through all its sonic techniques. It's constantly reminding us of the physical role our tongue plays in creating language, just as much as it emphasizes the personal role that language plays in our lives.