Development of a new method for deriving initial fittings for hearing aids with multi-channel compression: CAMEQ2-HF

Abstract

Abstract

described a procedure, CAMEQ, for the initial fitting of multi-channel compression hearing aids. The procedure was derived using a model of loudness perception for impaired hearing. We describe here the development of a new fitting method, CAMEQ2-HF, which differs from CAMEQ in the following ways: (1) CAMEQ2-HF gives recommended gains for centre frequencies up to 10 kHz, whereas the upper limit for CAMEQ is 6 kHz; (2) CAMEQ is based on the assumption that the hearing aid user faces the person they wish to hear and uses a free-field-to-eardrum transfer function for frontal incidence. CAMEQ2-HF is based on the assumption that the user may wish to hear sounds from many directions, and uses a diffuse-field-to-eardrum transfer function; (3) CAMEQ2-HF is based on an improved loudness model for impaired hearing; (4) CAMEQ2-HF is based on recent wideband measurements of the average spectrum of speech.

Sumario

describieron un procedimiento, CAMEQ, para la adaptación inicial de auxiliares auditivos con compresión de múltiples canales. El procedimiento se basó en el uso de un modelo de percepción de la intensidad subjetiva para casos de audición disminuida. Describimos aquí el desarrollo de un nuevo método de adaptación, CAMEQ2-HF, que difiere del CAMEQ en las siguientes formas: (1) CAMEQ2-HF proporciona ganancias recomendadas para las frecuencias centrales hasta 10 kHz mientras que el límite superior para el CAMEQ es 6 kHz; (2) CAMEQ se basa en la suposición de que el usuario de un auxiliar auditivo (se ubica de frente)hace frente a la persona que quiere oír y usa la función de transferencia campo libre-membrana timpánica para una incidencia frontal. CAMEQ2-HF se basa en la suposición de que el usuario quiere oír los sonidos desde muchas direcciones y usa una función de transferencia campodifuso-a-membrana timpánica; (3) CAMEQ2-HF se basa en un modelo de intensidad subjetiva mejorada para la audición disminuida; (4) CAMEQ2-HF se basa en las recientes mediciones de banda ancha del espectro promedio del habla.

Key Words:

• Hearing aids
• Fitting
• Multi-channel compression
• Automatic gain control

Acknowledgements

This work was supported by the MRC (UK). Additional support was provided by Starkey (USA) and by Earlens Corporation (USA). We thank Tom Baer and Christian Füllgrabe for their assistance with various aspects of this work. We thank Larry Revit and an anonymous reviewer for very helpful comments on an earlier version of this paper.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.