
Closed
Posted
Paid on delivery
I need a production-ready, real-time voice-changing application for my call-center environment. Agents must be able to switch among six high-quality U.S.-accented voices—three male and three female—without audible lag while they are on live VoIP calls. Clean, natural-sounding tone modulation is essential; the result should feel like a genuine human voice rather than a gimmick. The desktop client has to run smoothly on both Windows and macOS and sit between the agent’s headset and any softphone, SIP desk phone, or WebRTC browser tab. Latency must remain low enough that neither party notices a delay, even during high-traffic periods. An accompanying web-based admin panel lets me create, suspend, and delete user accounts, set seat limits, and pull usage reports by user, date range, and chosen voice. CSV or JSON export for those reports is preferred so I can feed them into our BI tools later. I am open to whichever DSP, AI, or machine-learning stack you feel delivers the most natural result—whether that’s C++ with a custom neural network, a Rust audio engine, or a Python/TensorFlow backend—as long as deployment for both operating systems is straightforward. Deliverables • Agent-side application for Windows & macOS (installer or signed package) • Web admin portal with user-management and reporting features • Documentation covering installation, configuration, and an API (if exposed) • A brief demo session that proves the voices work in real-time on a live SIP or WebRTC call Acceptance criteria • Sub-150 ms end-to-end latency during a two-way VoIP call • Clearly distinguishable U.S. male and female voices with no robotic artifacts • Successful generation of per-user usage reports from the admin panel Please include a short outline of your proposed technical approach and any past work that demonstrates real-time audio processing expertise when you reply.
Project ID: 40648158
26 proposals
Remote project
Active 2 days ago
Set your budget and timeframe
Get paid for your work
Outline your proposal
It's free to sign up and bid on jobs
26 freelancers are bidding on average ₹27,344 INR for this job

Hi, Your latency and production-readiness requirements point to an architecture where real-time audio processing is prioritized over post-processing quality. I'd build this with a modular pipeline so the desktop client and admin platform can evolve independently. Methodology: Build a low-latency audio pipeline that sits between the headset and SIP/WebRTC audio stream. Use an AI/DSP voice-conversion engine optimized for sub-150 ms end-to-end latency with six selectable U.S.-accent voice profiles. Develop cross-platform desktop clients (Windows & macOS) with seamless voice switching during live calls. Create a secure web admin panel for user management, seat limits, and per-user usage analytics. Store usage events in a structured database with CSV/JSON exports and future BI integration in mind. Validate performance through live SIP/WebRTC testing, latency measurements, audio quality checks, and multi-user load testing before handover. The focus is a scalable, production-ready solution that delivers natural voice conversion while leaving room for future voice profiles and enterprise integrations.
₹25,000 INR in 15 days
7.0
7.0

Hello, I’ve gone through your project details and this is something I can definitely help you with. I have 10+ years of experience in mobile and web app development, working with Flutter, Android, iOS, React, Node.js, and APIs. I focus on clean architecture, scalable code, and clear communication to ensure the project runs smoothly from start to finish. I will first review your requirements, suggest the best technical approach, and then proceed with development while keeping you updated at every stage. Here is my portfolio: https://www.freelancer.in/u/ixorawebmob I’m interested in your project and would love to understand more details to ensure the best approach. Could you clarify: 1. Do you need this for mobile, web, or both? 2. Do you already have UI/UX designs or should we create them? 3. Will there be any third-party API or payment gateway integration? 4. What is your expected timeline for completion? 5. Are there any reference apps or websites you like? Let’s discuss over chat! What specific features are most critical for the real-time voice-changing application? Regards, Arpit Jaiswal
₹27,750 INR in 33 days
7.4
7.4

Hello Client, Given my extensive experience of 14 years focused on Web and APP development, I am well-versed in the technologies you've mentioned including HTML, CSS, JavaScript, jQuery, and React.js Just as you value clean, natural-sounding voice modulation in your project, I deeply believe in smooth, bug-free software. In addition to possessing highly efficient skills in Mobile App Development (Ionic, Flutter, iOS, Android) and Python - I can guarantee a high-quality voice-changing application that will even impress seasoned call-center agents. My technical approach towards this task would be employing Django / Flask framework from Python for building a highly maintainable backend service layered with an intuitive frontend using ReactJS or AngularJS. This will ensure that the application not only meets your requirements but can be easily maintained and scaled up in the future. Regards, Manish
₹25,000 INR in 7 days
5.5
5.5

Hi, I can build this as a production-grade, low-latency desktop voice-processing solution for Windows and macOS, with a web-based administration and reporting layer. My proposed architecture is a native audio engine using C++/Rust with WASAPI/Core Audio, optimized for real-time DSP/voice conversion, exposed to the desktop client through a lightweight cross-platform UI. The six voices would be processed locally where possible to minimize network dependency and latency, with careful buffering and CPU optimization targeting your <150 ms end-to-end requirement. The admin portal will provide secure user/seat management, voice assignment, suspension/deletion, usage tracking, date/voice/user filtering, and CSV/JSON exports. I’ll deliver signed installers, backend/admin portal, API documentation, deployment documentation, testing, and a live SIP/WebRTC demonstration. I can also provide relevant real-time audio/DSP examples and discuss the exact voice-conversion technology after reviewing your call environment and hardware requirements.
₹25,000 INR in 7 days
4.8
4.8

Hi, Your project "Real-Time Call-Center Voice Changer" is a good fit -- Python backend and automation work is my main line of work. How I would run it: 1. Confirm the inputs, outputs and edge cases in writing first, so there is no ambiguity about what the script or service has to handle. 2. Build it in small reviewable pieces with tests around the parts that touch real data, rather than one large drop at the end. 3. Deliver clean, documented code with a requirements file and setup notes, so you or another developer can run and extend it without me. Matching your listed skills: Asterisk PBX, Audio Engineering, Audio Processing, C++ Programming, Mobile App Development, Python, Software Development, Voice Over, VoIP, WebRTC. My bid is ₹31875, within your ₹12500-37500 range. Let's connect to discuss this further -- happy to walk you through how I would structure it and answer anything you want covered first. Thanks for your time. Best regards, Ashish & Team
₹31,875 INR in 7 days
4.6
4.6

As an accomplished technology specialist with extensive experience in real-time audio processing, DSP, AI and machine-learning stacks, I'm excited to engage with your project of building a production-ready real-time voice-changing application. My approach would be to leverage my C++ programming skills to design a custom neural network that accentuates a seamless, high-quality voice transition between the six distinct accents. Furthermore, my proficiency in software development extends to Windows and macOS platforms, allowing for the smooth implementation of the desktop client that you require for your agents. I also bring considerable expertise in building web-based admin panels that would effectively manage user accounts, seat limits, and provide extensive reporting for usage analysis. To guarantee long term maintenance and ease of use, the provision of comprehensive documentation for installation, configuration and API usage will be included in the deliverables. In terms of communication and analytics, I can ensure the export compatibility of usage reports into formats like CSV or JSON, which you can seamlessly integrate into your BI tools. My track record showcases my dedication to not only meeting but exceeding client expectations through optimized solutions that are efficient, reliable, and scalable for long-term growth.
₹12,500 INR in 5 days
4.6
4.6

As a highly skilled and versatile technology specialist, I bring more than just a mobile app development and Python proficiency to the table. I offer a holistic service that spans from branding to software, AI to cloud, DevOps to automation - all of which play crucial roles in creating your custom voice-changing application. With my comprehensive knowledge of AI, I am well-equipped to navigate various stacks including C++, Rust, and Python/TensorFlow to design a solution that best aligns with your requirements. My past work on developing and fine-tuning deep learning models such as OpenAI (GPT) and Hugging Face demonstrates my expertise in real-time audio processing - a skill necessary for this project.
₹25,000 INR in 3 days
4.4
4.4

hi sir i am working in singapore voip company so i can easily handle ur project i am very perfect in ASTERIK so ping me disucss on pm ........................................................................................................................................................................
₹35,000 INR in 7 days
1.3
1.3

Hi, You need more than a basic voice changer—you need **production-grade, low-latency audio processing that works reliably during real VoIP calls**. I can build this as a cross-platform desktop audio engine with virtual audio routing, optimized real-time voice processing, and a web-based admin portal. My approach would focus on **sub-150 ms end-to-end latency**, natural-sounding male/female U.S. voices, efficient CPU/GPU processing, and reliable integration with SIP, softphones, and WebRTC. The admin panel would include account/seat management, usage tracking, filtering, and CSV/JSON exports. I’ll also provide installers, documentation, API details where applicable, and a live SIP/WebRTC demonstration. **Message me now to discuss your architecture, voice requirements, and project timeline.**
₹12,500 INR in 1 day
0.0
0.0

Hi Client! The main challenge is delivering natural voice conversion during live calls with sub-150 ms latency across Windows and macOS. The system also needs stable VoIP/WebRTC integration without audio drops or noticeable delay during high traffic. I’ll build a low-latency Audio Processing engine using C++/Python where suitable, with WebRTC/VoIP integration and six distinct U.S. voices. I’ll also create the web admin portal for user management, seat limits, usage reports, and CSV/JSON exports. The solution will be tested with Asterisk PBX and live SIP/WebRTC calls, with proper Audio Engineering, performance testing, and deployment documentation. Do you already have a preferred VoIP/softphone environment, or should I design the audio routing layer to support SIP, WebRTC, and standard desktop softphones? Start /Open chat now.
₹18,000 INR in 7 days
0.0
0.0

Hi, Your biggest challenge here isn’t simply changing pitch, it’s achieving **natural voice conversion while keeping the complete VoIP audio path under 150 ms**. That’s exactly how I’d approach the build. I can develop a production-ready Windows + macOS desktop application that operates as a virtual audio layer between the agent’s headset and SIP/WebRTC softphone, with **6 selectable U.S.-accented voices (3 male, 3 female)**. I’ll specifically benchmark **capture → conversion → playback latency** throughout development rather than leaving latency testing until the end. For delivery, I’d suggest milestones covering the real-time audio prototype first, followed by cross-platform packaging, admin/reporting, and final live SIP/WebRTC testing. Before starting, I’d like to confirm which softphones/SIP environment you currently use and your typical agent workstation specifications. Ready to discuss the architecture and begin with the latency-critical prototype.
₹25,000 INR in 7 days
0.0
0.0

Thanks for detail. I have worked on real time audio processing systems. So I know this workflow well. I can make you get good result quickly. Thanks Jefry
₹25,000 INR in 8 days
0.0
0.0

Hello, thank you for your detail Your project matches well with my exprience in real-time audio, C++/Python development, VoIP/WebRTC, and desktop applications. I will focus first on the audio pipeline and latency, because that will decide the whole project. The plan would be to capture the microphone stream, apply the selected voice model in real time, and expose the processed audio as a virtual input that works with softphones and browser calls. Once that core is stable, I can add the six voice profiles, Windows/macOS packaging, and the admin panel for users, seats, and usage reporting. I’d start with a working latency/voice-quality prototype before building the full management layer. Thanks.
₹100,000 INR in 20 days
0.0
0.0

YOU DON’T LIKE THE WORK, YOU DONT PAY. I recently completed a similar voice processing project with outstanding results. I am confident I can deliver the same quality for your call-center voice changer. The requirement for low-latency, clean voice modulation caught my attention as it is crucial for seamless communication. Our solution will be highly **responsive**, **integrated**, and **scalable**. It will ensure an easy-to-use interface for both agents and administrators while maintaining a **professional** feel. While we might be new to Freelancer, we have over 5 years of experience off-site, and I truly appreciate you taking your time to review our proposal. I would love to discuss this project more. We have multiple 5-star reviews on similar projects and rank in the top 1% among 75 million users! The worst that can happen is you walk away with a FREE consultation. Regards, TJ
₹18,750 INR in 7 days
0.0
0.0

Hi client, I understand your project requirements, you need a real time voice changer that operates in-between the microphone driver and user applications like skype, meet, zoom and so on. My proposed architecture, install a virtual cable driver (a.k.a a virtual microphone driver), then provide a C++ or Python program that continuously takes short chunks audio from the the real microphone, applies the voice changing processor (either a fixed algorithm or a deep learning inference) and then passes the modified audio chunk to the cable. Now, users just have to choose the cable as their microphone (in zoom forexample), and their heard voice will sound as the choosen voice. Also the Web admin portal is a trivial task (that will definitely be the easier task). For related work, i've done a similar task before, a real time video upscaler for animes. If interested in my approach, leave me a message. Cheers,
₹25,000 INR in 5 days
0.0
0.0

I think this is a very strong and practical concept, particularly because you have clearly defined measurable acceptance criteria. My team and I can deliver the Windows/macOS applications, real-time audio processing engine, admin portal, reporting exports, documentation, and live-call demo. What is your expected maximum number of concurrent agents during peak traffic?
₹25,000 INR in 2 days
0.0
0.0

Hi there, I can build your real-time voice changer for Windows and macOS with sub-150ms latency using a native C++/Rust audio engine and optimized ONNX/TensorRT voice conversion models. Technical Approach: Low-Latency DSP Engine: C++/Rust pipeline captures microphone frames (10–20ms chunks) with real-time neural pitch/timbre conversion, routing seamlessly into softphones/WebRTC via a virtual audio driver. 6 Natural US Voices: 3 male and 3 female profiles trained with acoustic envelope matching to avoid robotic artifacts. Desktop Client: Cross-platform app (Windows/macOS) with instant profile switching and hotkeys. Admin Portal & Reporting: Web dashboard (FastAPI/React) for user seat management, voice assignments, and CSV/JSON usage log exports. Deliverables: Signed Windows & macOS client installers 6 tuned US voice models + virtual driver setup Web admin portal with BI export tools Complete documentation & live SIP/WebRTC demo Let's discuss your softphone setup and test a live audio demo. Best regards, Chetan Sai Raj
₹28,000 INR in 10 days
0.0
0.0

I can build this as a low-latency real-time voice conversion system for Windows and macOS, with a web-based admin panel for users, seat limits, usage tracking, and CSV/JSON reports. **Technical approach:** * Native C++/Rust audio pipeline for low-latency capture/playback * Lightweight neural voice conversion optimized for real-time inference * Virtual audio device integration for SIP, WebRTC, and softphones * FastAPI + PostgreSQL for the admin backend * Target <150 ms end-to-end latency I have hands-on experience with audio ML, PyTorch, LFCC-based audio processing, FastAPI, speech technologies, and deploying ML inference systems. I have also built a deepfake-audio detection system and worked with real-time speech/audio pipelines. I can start by validating the real-time conversion latency and voice quality before building the complete application.
₹15,000 INR in 15 days
0.0
0.0

Hi, I'm a Desktop Application developer with more than 3 years of experience. I can build you a modern Windows and macOS client with a login page that creates virtual microphone so your agents can use. I'd use C++ and Qt for the clients and Python and Django for the web-based admin panel that let's you edit/add your users. We will discuss more details about the AI tool that we will embed into the app. I'm looking forward to working with you on this exciting project.
₹25,000 INR in 7 days
0.0
0.0

i already have the solution contact me for more info But before I get too ahead of myself, let me first assure you that I'm fully equipped to deliver exactly what you need for your real-time call-center voice changer. With extensive experience in full-stack development, I've got you covered on all fronts of this project. Whether it's building a high-quality desktop client for both Windows and macOS or designing and implementing a comprehensive web-based admin panel, I've got the technical know-how to make it happen for you. When it comes to low latency and high-quality voice modulation, my stack expertise includes Python/TensorFlow, C++, and AI, which would be ideal for ensuring the naturalness of every voice change without any lag that could impact the call experience. The clean, maintainable code I produce is not only high-performance but leans into machine-learning and AI to process audio in real-time. Lastly, as a full-stack developer skilled in database design and optimization, I'm well-positioned to provide you with robust user-management and reporting features through your preferred CSV or JSON export format. You may also count on me for thorough documentation, including installation instructions and API details that are easy to follow. My commitment to long-term support after project delivery adds an extra layer of assurance for a smooth transition post-delivery. Let's get started on providing a top-notch solution that meets all your needs.
₹25,000 INR in 7 days
0.0
0.0

Kolkata, India
Payment method verified
Member since May 21, 2025
₹12500-37500 INR
₹1500-12500 INR
₹37500-75000 INR
₹37500-75000 INR
₹12500-37500 INR
₹100-400 INR / hour
$30-250 USD
$500 USD
$8-15 USD / hour
₹750-1250 INR / hour
$250-750 USD
$22 USD / hour
$30-250 CAD
$18.5 USD / hour
₹750-1250 INR / hour
$18.5 USD / hour
$15-25 USD / hour
$30-250 USD
₹600-1200 INR
$30-250 USD
$750-1500 USD
€12-18 EUR / hour
₹12500-37500 INR
$750-1500 CAD
$30-250 USD