Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Mission Critical Voice Quality of Experience Mouth-to-Ear Latency Measurement Method

The purpose of this software is to measure the mouth-to-ear (M2E) latency of a push-to-talk network. M2E latency characterizes the time between speech input into one communications device and its output through another. M2E latency has been identified as a key metric of quality of experience (QoE) in communications. NIST’s Public Safety Communications Research group developed this software to measure and quantify the M2E latency of Push To Talk (PTT) devices.

Obtaining Software

Code available at:

Data available at:

Paper available at

Related Software

Mission Critical Voice Quality of Experience Access Time Measurement Method

Mission Critical Voice QoE Firmware


Created January 24, 2020, Updated January 29, 2020