Effects of noise, nonlinear processing, and linear filtering on perceived music quality

Abstract

Abstract

Objective: The purpose of this study was to determine the relative impact of different forms of hearing aid signal processing on quality ratings of music. Design: Music quality was assessed using a rating scale for three types of music: orchestral classical music, jazz instrumental, and a female vocalist. The music stimuli were subjected to a wide range of simulated hearing aid processing conditions including, (1) noise and nonlinear processing, (2) linear filtering, and (3) combinations of noise, nonlinear, and linear filtering. Study sample: Quality ratings were measured in a group of 19 listeners with normal hearing and a group of 15 listeners with sensorineural hearing impairment. Results: Quality ratings in both groups were generally comparable, were reliable across test sessions, were impacted more by noise and nonlinear signal processing than by linear filtering, and were significantly affected by the genre of music. Conclusions: The average quality ratings for music were reasonably well predicted by the hearing aid speech quality index (HASQI), but additional work is needed to optimize the index to the wide range of music genres and processing conditions included in this study.

Sumario

Objetivo: El propósito de este estudio fue determinar el impacto relativo de diferentes formas de procesamiento de señal de los auxiliares auditivos en cuanto a la calificación cualitativa de la música. Diseño: la calidad de la música se evaluó utilizando una escala de calificación para tres tipos de música: clásica orquestral, jazz instrumental y mujer vocalista. Los estímulos musicales estuvieron sujetos a un amplio número de simulaciones de procesamiento de los auxiliares auditivos, incluyendo (1) ruido y procesamiento no-linear, (2) filtración linear y (3) combinaciones de ruido, no-linear y filtración linear. Mestra: Se obtuvieron los índices de calidad en un grupo de 19 sujetos normoyentes y otro grupo de 15 sujetos con hipoacusia sensorineural. Resultados: Las calificaciones cualitativas en ambos grupos fueron generalmente comparables, confiables en las diferentes sesiones, fueron más alteradas por el ruido y por el procesamiento no linear de la señal que por la filtración linear y fueron afectadas significativamente por el género de la música. Conclusiones: El índice de calidad del lenguaje de los auxiliares auditivos (HASQI), pronosticó razonablemente bien el promedio de calificación de la calidad de la música, pero todavía es necesario continuar la investigación para optimizar el índice para que éste pueda cubrir una gama más amplia de géneros y condiciones de procesamiento incluidas en este estudio.

Key Words::

• Hearing aid signal processing
• Sound quality
• Music and hearing aids

Acknowledgements

The authors thank Naomi Croghan for assistance in data collection and analysis, and Ramesh Kumar Muralimanohar for development of the software used for the listener tests. We thank Brian C.J. Moore for kindly sharing the jazz music stimulus. Portions of the data included in this paper were presented at the 157^th Meeting of the Acoustical Society of America, Portland, Oregon, 18–22 May 2009.

Declaration of interest: This work was supported in part by a research grant from GN Resound Corporation to the University of Colorado. James M. Kates is an employee of GN Resound Corporation.