Exposure to vibrotactile music improves audiometric performances in individuals with cochlear implants

Abstract

Vibrotactile stimulation has been shown to enhance the music listening experience of cochlear implant (CI) users. However, while existing studies have focused on music perception, significant gaps remain in our understanding of how music induces emotions in CI users and the role of vibrotactile stimulation in this process. Furthermore, the after-effects of audio-vibrotactile music listening on audiometric test performances have not yet been investigated on CI users. This paper presents a study in which two groups of twelve CI users were each exposed to music alone and to music with concurrent vibrotactile stimulation delivered via a vest enhanced with actuators. Standardized tonal and speech tests were conducted before and after both types of exposure (audio and audio-vibrotactile). In particular, speech audiometry was conducted in the quiet condition (with no masking sounds) for the first group and with the competing sounds for the second group. Results from both groups consistently showed that the exposure to tactile music significantly enhanced CI users' ability to decode tonal and speech signals compared to the effect resulting from exposure to sounds alone. The majority of participants preferred listening to music with concurrent vibrations over an audio-only experience, as it led to higher levels of immersion and engagement. Consistent with findings from previous studies on individuals with normal hearing, an increase in arousal in CI users was observed in the audio-vibrotactile condition compared to the absence of vibrations, regardless of the type of emotion being conveyed. Nevertheless, participants emphasized the need for vibrotactile devices to incorporate personalization mechanisms, allowing them to dynamically adjust vibration intensity for different body parts. These findings may open the door to novel therapeutic approaches for CI users.

Keywords: Cochlear implants; Haptic wearables; Human-computer interaction; Musical haptics; Speech audiometry; Tactile music enhancement.

Fig. 1

A picture of a participant during the experiment where it is possible to notice the components of the audio-vibrotactile system and the interface running on the laptop.

Fig. 2

Mean and standard error of the differences between post- and pre-experiment for the first experiment (involving speech audiometry in quiet). Legend: * = p < 0.05, ** = p < 0.01, *** = p < 0.001.

Fig. 3

Mean and standard error of the differences between post- and pre-experiment for the second experiment (involving speech audiometry with competing sounds). Legend: *** = p < 0.001.

Fig. 4

Arousal and Valence assessment for each of the 12 musical stimuli (see Table 3). According to the circumplex model of affect, happiness is placed in the high-valence high-arousal quadrant, sadness in the low-valence low-arousal quadrant, relaxation in the high-valence low-arousal quadrant, and aggressiveness in the low-valence high-arousal quadrant. For each emotional stimulus the corresponding quadrant is indicated in light gray.

Fig. 5

Mean and standard error for the five questionnaire items. Legend: *** = p < 0.001.