Digital Speech Standard

The Digital Speech Standard (DSS ) is a proprietary (ie, not open ), cross-manufacturer audio codec for low-loss storage of voice data into dictaphones.


Some years before the launch of the first digital voice recorders Grundig developed in collaboration with the University of Erlangen -Nuremberg in 1994 the first DSS codec. The DSS standard was assumed to be presented in 1997 as a joint development by Grundig, Olympus and Philips. At the same time founded the manufacturers involved an open standards body - the International Voice Association ( IVA ) - for the uniform specification and development of the DSS.

Due to high demands for device development and royalties DSS is used only in the professional equipment of the IVA- members.


The DSS audio codec that has been specially designed for storing human language and used as the far more popular MP3 psychoacoustic model. Thus, a relatively high compression ratio is achieved with only minor loss of quality. However, deteriorated by the lossy compression, the detection rate of computer-based speech recognition. This weakness was improved in the following standard "DSS Pro".

In addition to optimizing the memory requirements of the recordings more information can be added to the recordings. Thus, in the header files of the recordings, for example, an author identifier or something else be saved.

DSS files can be further processed by special software, the manufacturer of dictation solutions offer corresponding performance writing space software and workflow management programs. However, there are also free player programs. However, further processing with other software is not possible. The demonstration program is only available for Microsoft operating systems. Olympus there is a free software player for Mac OS X ( DSS Player Lite ) that can be loaded on the local webpage.

After a short examination of the DSS format, the following findings were obtained:

  • DSS is a container that can be used for the storage of different codecs.
  • Currently, two shooting modes are known: LP and SP. LP uses the G.723.1 codec.

The successor DSS Pro

The de facto standard for professional applications DSS has been slightly modernized in its second version: First, the sampling rate was increased to 16 kHz in order to further improve voice quality and to better satisfy the requirements of speech recognition software. So it is now possible with a DSS Pro Voice Recorder to pass his dictations directly to the speech recognition Dragon NaturallySpeaking. The first voice recorders with DSS Pro are the Philips DPM 9600 or 9620 and the Digta 420 in two slide switch variants of Grundig Business Systems. Olympus has now also brought to the DS- 5000 is a DSS Pro Dictaphone on the market.


  • Audio compression
  • Audio signal format