Telomerase is a riboprotein enzyme that adds hexamers to the telomeric ends of chromosomes, effectively preventing their shortening with each cell cycle. Telomerase is not normally active in somatic cells, with the exception of long lived cells such as memory lymphocytes. Many tumour cell types exhibit telomerase activity, and this is thought to play a role in their immortality. In situ studies will determine which cell types telomerase is expressed in and whether the levels of expression are equal throughout the tumour. An important consideration is the effect of HPDs on communication, particularly the ability to perform such auditory tasks as signal detection and discrimination, sound localization and speech understanding.
Industrial noise tends to have a low-frequency bias.
Significant increments may be realized by wearing a muff and plug in combination. In a recent study funded by DND, we looked at whether increasing low-frequency attenuation in this manner would be deleterious to speech understanding. Below 2 kHz, the combination provided as much as 30 dB more sound attenuation than either device alone. Our second research stream focuses on spatial hearing, an important component of communication. In a PSI funded study, we are currently exploring life-cycle changes in the utilization of binaural and spectral cues that underlies sound localization ability.