Effects of low-pass filtering on dialect and gender perception

Abstract

In addition to linguistic (message-related) information, spoken language includes indexical information related to the speaker characteristics (e.g., gender, social status, and regional identity). This study is an extension of Jacewicz et al. (2015, JASA, 137, 2417–2418) which explored the nature of acoustic cues signaling indexical information. That study demonstrated that listeners were quite accurate in making decisions regarding the regional dialect and gender of a speaker when responding to short unprocessed phrases from 40 speakers (male and female) from two different dialects spoken in central Ohio and western North Carolina. However, when the signal was low-pass filtered at 400 Hz, sensitivity to both dropped significantly. The current study examined performance on the same phrases when the signal was low-pass filtered at progressively higher cutoff frequencies (500, 700, 900, and 1100 Hz). These stimuli were played to 20 listeners (10 males and 10 females) who identified the sex and dialect of the speaker. As expected, listener sensitivity improved with each wider low-pass filter condition. Performance in the 1100-Hz cutoff condition was very similar to that in the unprocessed condition. Discussion will focus on the nature of the acoustic cues utilized by listeners across the four low-pass filter conditions.