BANGALORE, India — Fifteen years ago I came to Bangalore, India’s Silicon Valley, to do a documentary on outsourcing. One of our first stops was a company called 24/7 whose main business was answering customer service calls and selling products, like credit cards, for U.S. companies half a world away.

The beating heart of 24/7 back then was a vast floor of young phone operators, most with only high school degrees, save for a small pool of techies who provided “help desk” advice. These young Indians spoke in the best American English, perfected in a class that we filmed, where everyone had to practice enunciating “Peter Piper picked a peck of pickled peppers” — and make it sound like they were from Kansas not Kolkata.

The operations floor was so noisy from hundreds of simultaneous phone conversations that 24/7 installed a white-noise machine to muffle the din, but even then you could still occasionally hear piercing through the cacophony some techie saying to someone in America, the likes of: “What, Ma’am? Your computer is on fire?”

Well, 24/7’s founders — P.V. Kannan and Shanmugam Nagarajan — invited me back last week for an update. Their company is now called [24]7.ai and their shop floor is so quiet that the operators are encouraged to play their own music. The only noise is from the tapping on keyboards, because every query — from customers of U.S. retailers, banks and media companies — is coming in by text messaging from smartphones, tablets , desktops and laptops.