AudiologyOnline Phone: 800-753-2160

What is the ISTS signal?

Maria Løye Samsson, MA

September 19, 2011



What is the ISTS signal?


ISTS (International Speech Test Signal) is an internationally recognized test signal that may be used in the technical evaluation of hearing instruments, and for probe-microphone measurements.. It was created based on the need for a standard test stimulus that included all the relevant properties of speech and allowed for reproducible measurement conditions. It is based on natural recordings of speech which is non-intelligible due to remixing and segmentation. The signal reflects a female speaker for six different mother tongues (American English, Arabic, Chinese, French, German, and Spanish) reading "The north wind and the sun".

The ISTS is shaped according to the LTASS (Long Term Average Speech Spectrum) standards. For more information, please refer to:

Holube, I. & EHIMA-ISMADHA Working Group. (2006). Short description of the international speech test signal (ISTS). Center of Competence HörTech and Institute of Hearing Technology and Audiology, Oldenburg, Germany.

Maria Løye Samsson has a Master's degree in Speech and Hearing Sciences from University of Copenhagen, Denmark. She began her career in GN Resound as a research audiologist, and currently works as Clinical Audiologist with Interacoustics A/S where her main focus is on hearing aid fitting and verification. In order to strengthen the partnership between Oticon and Interacoustics, Maria works from Oticon headquarters 2-3 days a week. For more information about Interacoustics, visit or the Interacoustics web channel on AudiologyOnline.

Maria Løye Samsson, MA

Clinical Audiologist

Our site uses cookies to improve your experience. By using our site, you agree to our Privacy Policy.