Single-Channel Vibrotactile Feedback For Voicing Enhancement In Trained And Untrained Perceivers

Abstract

Speech intelligibility can be enhanced by integrating information from other modalities, e.g., vision (Sumby & Pollack 1954) or direct manual touch (Gick et al. 2008).  There are, nonetheless, many circumstances where shared visual attention may be hard to establish, or where in-person contact may be infeasible (e.g., in a noisy collaborative environment). We use vibrotactile feedback to enhance intelligibility in acoustically noisy conditions by providing stimulation in a manner similar to the laryngeal vibrations felt during voiced speech. Participants were asked to discriminate between words in noise, distinguished in voicing and vowel height. In a pilot study we contrasted vibrator placement (fingers vs. neck) with different vibration styles. In untrained perceivers we found that vibrotactile feedback increased accuracy regardless of placement. This effect, though significant, was not strong enough to be useful for everyday speech enhancement. We then conducted a full study using trained participants and found strong evidence for vibrotactile enhancement of speech intelligibility in acoustically noisy environments.