Frequency characteristics and speech recognition in cartilage conduction

Publication date: Available online 19 January 2019

Source: Auris Nasus Larynx

Author(s): Tadashi Nishimura, Ryosuke Miyamae, Hiroshi Hosoi, Osamu Saito, Ryota Shimokura, Toshiaki Yamanaka, Tadashi Kitahara

Abstract

Objective

Cartilage conduction (CC) is a new transduction form, and hearing devices that utilize CC present a new option for patients with aural atresia. However, in occluded ears, low-tone sounds are transmitted very effectively, resulting in excessive low-tone sound emphasis and speech recognition reduction. This study aimed to clarify low-tone speech recognition for CC in occluded ears, and determine if excessive low-tone sound emphasis decreases maximum speech recognition scores.

Methods

Eight volunteers with normal hearing participated. The performance-intensity function and maximum speech recognition scores for CC with an earplug (i.e., occluded) and air conduction (AC) were measured under high- and low-pass filter (HPF and LPF) conditions, respectively.

Results

An HPF improved the maximum speech recognition scores for CC in occluded ears. The scores for CC (occluded) under the conditions of the first- and second-order HPF did not differ from that for AC under the no-filter condition. Conversely, an LPF reduced the scores for AC. The scores and confusion matrices under the second-order LPF condition were similar to those for CC (occluded).

Conclusion

The conditions under the second-order LPF resembled those of CC in occluded ears. An HPF can compensate excessive low-tone emphasis and improve speech recognition.

http://bit.ly/2W8sx8G