What is BEST?

BEST  (Bremen Emotional Sound Toolkit) is a validated set of 408 short (700ms to 16s) electronic sound emblems. Some sample sounds from the toolkit are provided below:

How we used BEST in the EMOTE Project

The affective sounds were created for the EMOTE  project to augment the nonverbal capabilities of the NAO robot. NAO is not able to modulate facial expressions and only limited means exist for modulating head and torso position. The text-to-speech (TTS) synthesis employed is also not capable of generating paralinguistic cues to express different emotional states. To address these challenges the idea was developed to create hybrid sounds that involve the generation of TTS with attached sound emblems.


We allow the free usage of this sound set for noncommercial academic and hobby purposes (for any commercial usage, enquire at The sounds contained in the BEST are primarily intended to be used as short audible utterances and augmentation of utterances for robots and electronic systems of any kind. Detailed tables and additional visual selection tools are provided to facilitate a quick selection of positive, negative, low activating, and high activating sounds but also for differential emotions (based on the Differential Emotions Scale, DES) as well as in the context of a small selection of pre-defined speech acts. The sounds can, however, be used together with any other software or system sounds, or for the creation of digital audio-visual artwork or instructional content.


No other hardware or software is required to use BEST, expect to uncompress the content and play the sound files. All sound files are provided as simple .wav files.

Supporting Materials

An Excel table with suggested selection criteria is bundled with the download. All further details regarding the construction and validation of the sound set is included with the accompanying EMOTE deliverable (D3.2).