Whistl

If you grew up in an Indian household, you’ve heard this countless times. The COVID-19 pandemic got me more involved in kitchen activities, and suddenly this age-old request became… well, really annoying.

After burning rice twice and constantly running around the house asking if anyone heard whistles, my design instincts kicked in. I knew I couldn’t be the only one facing this problem.

the problemPermalink

Traditional pressure cookers have been part of Indian kitchens for generations. Counting whistles to determine cooking time is deeply embedded in our cooking culture. But in 2021, with everyone working from home, studying online, and living in multi-story houses, keeping track of cooker whistles had become a genuine pain point.

The more I thought about it, the more complex this “simple” problem became:

• Whistle duration matters – quick puffs don’t count toward the tally
• Responsibility delegation – mom asks someone else to listen while she’s in a Zoom meeting
• Multi-story homes – impossible to hear kitchen sounds from upstairs rooms
• Distractions – people would rather continue their Netflix binge than stand in the kitchen

solutionPermalink

validating the whistle conundrumPermalink

Before building anything, I needed to understand if this was actually a widespread problem or just my personal frustration.

I conducted a mixed-method research study starting with a survey about rice cooking methods in Indian kitchens.

• Majority of Indian households still use traditional whistle cookers
• 54% of people who used pressure cookers found it problematic (overcooking, undercooking, burning)
• Young adults (20-27) struggled most, as expected
• Surprisingly, many people still used open utensils for rice cooking

research insights from interviews

Key behavioral patterns I discovered:The delegation problem:“When mom has to get ready for work, she asks me to listen for whistles. I agree reluctantly but usually forget.”The multi-story challenge:“In our house, the kitchen is downstairs and rooms are upstairs. It’s impossible to hear whistles, so someone has to sit near the kitchen.”The priority conflict:“I’d rather continue my assignment or yoga session than count whistles, but I feel guilty saying no.”The milk overflow bonus problem:

Many participants mentioned forgetting to turn off milk while boiling – a related kitchen timing issue that could be addressed later.

Two distinct personas emerged:

1. The Reluctant Helper – asked to listen but prefers doing other activities
2. The Busy Cook – manages multiple tasks and needs reliable whistle tracking

the energy efficiency experimentPermalink

Before designing a solution, I wanted to understand if forcing people to change cooking methods was worth it. I conducted experiments comparing:

1. “Correct” method – build pressure on high heat, then simmer
2. “Convenient” method – let it whistle and count a set number

Using an induction cooktop to measure energy consumption, I ran multiple tests for both methods.

The surprising result: Energy consumption was almost identical between both methods.

This meant the solution wasn’t about changing behavior… it was about supporting existing behavior with better tools.

building the whistle detectorPermalink

the technical challengePermalink

Creating Whistl required solving two core problems:

1. Seamless recognition of cooker whistles in noisy kitchen environments
2. Accurate counting and reliable user notifications

• 1 month of recording cooker whistles with smartphone microphones
• Various kitchen settings to simulate real-world usage
• Manual parsing to create “Whistle” vs “Noise” labeled dataset
• 16kHz sampling rate standardization for consistency

• Used CreateML framework’s sound classification template
• Built a Neural Network that was both accurate and lightweight
• Final model: just 4.6MB with 99% accuracy in whistle detection

design philosophy for utility

Interface design principles:

Given the utilitarian purpose of the app, simplicity was paramount:

• Black as primary color for clean, distraction-free interface
• Tints of black to establish clear visual hierarchy
• San Francisco font for familiarity and readability
• Minimal cognitive load – anyone should be able to start using immediately

Core user flow:

1. Set desired number of whistles
2. Start detection
3. App listens and counts automatically
4. Notification when target is reached

Notification flexibility:

• In-app alerts
• SMS to another person
• Automated phone calls for maximum attention-grabbing

prototype testing insightsPermalink

Phone calls > other notifications: “I prefer getting a phone call when all whistles are counted – it’s harder to miss than SMS.”

Alarm preferences: “SMS notifications are easy to miss. An alarm would be better at grabbing attention.”

Technical constraints: While users wanted alarm notifications for others, this would require client app installation on recipients’ phones, complicating adoption. Automated phone calls provided the intrusion level users wanted with simpler implementation.

• Real-time whistle detection and counting
• Multiple notification methods (in-app, SMS, phone calls)
• Contact delegation – notify someone else when cooking is done
• Simple, distraction-free interface optimized for kitchen use

looking beyond the kitchen timerPermalink

the broader impactPermalink

While Whistl might seem like a simple utility app, the research process uncovered fascinating insights about Indian kitchen practices:

• Energy efficiency wasn’t significantly different between cooking methods
• Behavioral change wasn’t necessary – technology could adapt to existing habits
• Cultural practices (like counting whistles) weren’t inefficiencies to fix, but behaviors to support

Platform considerations: Given Android’s dominance in the Indian smartphone market, the plan was to rewrite in Flutter for wider cross-platform reach and bigger impact.

the bigger picturePermalink

This project reinforced a fundamental truth about design: We have problems everywhere, it’s just a matter of noticing them and solving them.

What started as personal frustration with kitchen chores became a deep exploration of cultural practices, family dynamics, and technological solutions. The “whistle conundrum” wasn’t just about cooking… it was about how technology can respect and support the ways people actually live.

Whistl proved that machine learning and thoughtful UX design could solve surprisingly specific problems. Sometimes the most impactful solutions come from addressing the small frustrations we’ve learned to accept as “just how things are.”

The meta-lesson: Great product opportunities often hide in plain sight, disguised as minor annoyances we’ve learned to live with. The key is noticing them, validating they’re shared problems, and building solutions that fit naturally into existing behaviors.