SoftBank Commercializes “SoftVoice,” an AI System That Moderates Aggressive Customer Calls

While Japan is well known for high standards of customer service, "kasuhara," an abbreviation of "customer harassment" that refers to unreasonable behavior from customers during interactions with service staff, has become a serious social issue. The authorities are beginning to take action: starting October 2026, Japan's Ministry of Health, Labour and Welfare will require companies to implement countermeasures that protect employees on the frontlines from kasuhara-related psychological harm.

Against this backdrop, SoftBank Corp. (TOKYO: 9434) has been developing technology to address the issue of customer harassment, using research conducted jointly with Shinnosuke Takamichi, a Project Associate Professor at The University of Tokyo's Graduate School of Information Science and Technology.

On February 2, 2026, a press conference was held in Tokyo to announce the official commercial launch of "SoftVoice," an AI-powered voice altering solution designed specifically for call centers. The system uses real-time AI voice conversion technology to soften aggressive customer tones during calls while preserving the original content.

Modulating voice tones while preserving the underlying meaning

SoftVoice analyzes acoustic features such as pitch and intensity during phone calls and adjusts aggressive tonal characteristics into calmer ones for the operator. Crucially, the semantic content of the speech remains intact. Only the perceived hostile tone of voice is dampened.

In tests conducted during development, the system achieved a greater than 30% reduction in a perceived anger evaluation index compared to unprocessed audio. Testing also confirmed the system had no measurable negative impact on call quality or operator handling times.

These results suggest the system can reduce the psychological stress of employees without disrupting operational efficiency: a key consideration in high-volume call center environments.

A four-layer protection framework

Beyond tone moderation, SoftVoice integrates additional features designed to support call center workers:

• Automated escalation warnings: a three-stage automated message system can issue policy-aligned warnings in cases of abusive language or excessively long calls, helping to de-escalate emotional confrontations.
• AI-powered noise suppression: reduces background noise to improve call clarity and reduce cognitive load.
• Call recording: supports compliance, quality control and risk management.

Taken together, these features position SoftVoice as a comprehensive system that protects and assists operators, rather than just being a single-purpose tool.

AI to protect the mental health of service sector employees

Unlike many AI applications used in the customer service sector that focus on automation or workforce reduction, SoftVoice is designed to assist human workers. By preserving what customers say while moderating tone of voice, the system avoids altering speech content or censoring the content of complaints.

With customer harassment becoming both a well-being issue at the workplace and a regulatory consideration, SoftVoice arrives at a pivotal moment. As companies prepare for mandatory countermeasures, the solution shows how AI can help safeguard the mental health of workers while maintaining high service standards.

"We see SoftVoice as a psychological shield for employees on the frontlines," said Toshiyuki Nakatani, a member of the SoftVoice development team at SoftBank's SaaS Planning Promotion Office. "By making the implementation of measures to counter customer harassment a standard practice, we hope to help build a sustainable society where people can continue to work with peace of mind."

(Posted on February 19, 2026)
by SoftBank News Editors