A digital hearing aid that compensates loudness for sensorineural hearing impairments. - Juan Carlos Tejero-Calado; Sebastián Bernal Zafra; José Antonio Hidalgo López; José Fernández Ramos; Rafael Urquiza de la Rosa; Alfonso Gago (ICASSP, 1995)

Frequency lowering using a discrete exponential transform. - C. M. Aguilera; A. Navas; Rafael Urquiza de la Rosa; Alfonso Gago (EUROSPEECH, 1999)