Telephone speech enhancement for elderly hearing-impaired listeners
Amy E. Sheffield, Ashok Kumar Krishnamurthy, Lawrence L. Feth, Stephanie A. Davidson, Evelyn M. Hoglund, Lynette Roth · The Journal of the Acoustical Society of America · 1999
Many elderly persons with high-frequency hearing loss find telephone use frustrating due to lower intensity levels and reductions in acoustical information that can be useful in deciphering speech. The purpose of this project is to pre-process the speech signal before it is sent over the phone line and provide speech enhancement without the use of amplifying handsets or hearing aids at the receiving end. The enhancement technique takes into account the limited bandwidth of the phone line as well as the hearing characteristics of the user. Two pre-processing schemes, a single channel and a double channel approach, used to increase the intelligibility of speech in these situations are discussed. The single channel method performs amplitude compression of the entire signal. The two-channel method filters the incoming signal into high-frequency and low-frequency channels and performs independent compression on each before recombination. Results comparing the two speech enhancement schemes against no processing for a group of elderly hearing-impaired subjects are presented. [Work supported by a grant from the Franklin County Office on Aging.]