Ditech recently concluded an audit of mobile service over 16 operators in 12 countries and was startled by the number of calls affected by voice quality impairments originating in the caller's environment or a mobile handset or headset. Ditech concluded that this issue with voice quality is a leading contributor to subscriber churn.
The Mountain View, Calif., company also said the high percentage of unacceptable calls is a possible indication that the mobile services industry is struggling to deliver on the promise of mobility, which is that the service can deliver acceptable voice quality no matter where the call is made, or what device is used.
The data was obtained from more than 630 million live mobile calls originating in a general mix of urban and rural areas. The network technologies audited were GSM, CDMA and iDEN. Ditech's audits and its final report focus on ambient noise and acoustic echo, which tend to be the most prevalent impairments that degrade voice quality in mobile networks.
Findings of the audit include:
- The average percentage of calls that fall below the industry minimum standard for voice quality is 39%, which is often called the "churn zone." Industry research has shown that calls falling below the industry minimum for voice quality often lead to churn, which is when dissatisfaction is so strong that the subscriber terminates service.
- In mature markets such as the United States and Western Europe, 23% of all calls fell below the industry minimum.
- In rapid growth markets, such as the Middle East, India and South America, 59% of all calls fell below the industry minimum.
- Ambient noise, or noise that originates in the caller's environment and enters the device's microphone, was rated "objectionable" on up to 50% of all calls in some regions.
- Acoustic echo, which is often caused by mobile handsets and headsets, was rated "objectionable" on up to 11% of all calls in some regions.
- Voice level mismatch, which makes it sound like a caller is speaking either too loudly or too softly, was rated "objectionable" on up to 28% of all calls in some regions.