A New THD+N Algorithm for Measuring Today’s High Resolution Audio Systems

In this paper, a mathematical definition of Total Harmonic Distortion + Noise suitable for testing high-resolution digital audio systems is presented. This formal definition of the “distortion analyzer” mentioned in AES17 defines THD+N as the RMS error of fitting a sinusoid to a noisy and distorted sequence of measurements. We present the key theoretical result that under realistic conditions a modern THD+N analyzer is well-described by a Normal probability distribution with a simple relationship between relative error and analysis dwell time. These findings are illustrated by comparing the output of a commercial distortion analyzer to our proposed method using Monte Carlo simulations of noisy signal channels. We will demonstrate that the bias of a well-designed distortion analyzer is negligible.

Authors: Alfred B. Roney The Mathworks, Inc. (formerly Listen, Inc.) Steve Temme, Listen, Inc.
Presented at AES 2018, New York, NY.

Full Paper

Seminar in Japan: High Resolution Audio Measurements and Loudspeaker Design.

Two speakers will feature at this afternoon seminar focusing on high resolution audio measurements and Loudspeaker design. Steve Temme of Listen, Inc. will discuss the challenges of measuring high resolution audio. He will share his experience measuring devices up to 100kHz, and discuss which measurements give a meaningful insight into how the device sounds. Shinji Koyano of KOYANO Sound Lab (formerly of Pioneer) will discuss the basic theory and principles of loudspeaker design, focusing on recent technology. He will also present a case study of High-res technology on speakers.

Date & Time: October 15, 13:00-15:30

Cost: No charge

Location: US Embassy Tokyo Japan, 1-10-5 Akasaka, Minato-ku, Tokyo 107-8420 JAPAN

Hosted by: AudioTech in conjunction with the commercial services of the US Commerce Department

To register: Please contact Tom Teraoka at Audiotech


Seminar in Korea: Acoustic Measurement Using SoundCheck

In this one-day seminar, Listen President Steve Temme will discuss current topics in audio measurement including high resolution testing, Bluetooth testing, headphone testing and open loop testing. He will discuss the current state of the art for making these measurements, and demonstrate how to measure devices such as microphones within tablets and smartphones, Bluetooth headsets, and high resolution headphones using the SoundCheck test system.

Date & Time: October 13, 2015.  10am – 5pm

Cost: No charge

Location: NSSC Education room, NSSC, M-City Tower 9th, 195 Beakma-ro, Janghang-dong, Ilsandong-gu, Koyangcity, Kungki-do

Hosted by: Acetech Inc. and NSSC

To register: Please contact DH Kim at Acetech Inc. 010 4929 2760