Subject: Re: AUDITORY Digest - 24 May 2007 to 25 May 2007 (#2007-115) From: Fatima Husain <fthusain@xxxxxxxx> Date: Sun, 27 May 2007 14:16:38 -0400 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>There were several suggestions in response to my question. Thank you again. I am posting a compilation below. Trying to understand this leads me to some comments and a question: For speech and speech-like stimuli there appears to be an effect of high freq HL (hearing loss) on perception at low-frequencies. Because of reorganization, there is an improvement of the discrimination of frequencies at the edge of the hearing loss (but how far does this extend?) There may be a global change is loudness sensitivity (gain?) due to high freq HL. There may be a global change in ITD thresholds. Question: Would the perception of low freq simple stimuli (say pure tone at 1 KHz) be affected by high freq HL beginning at 8+ KHz and in what manner? Other non-speech but more complex stimuli like combinations of narrow-band FM sweeps? Fatima Fatima Husain, Ph.D. --------------------------------------------------------------------------------------------------------- 1] From Ben Hornsby Horwitz, A. R., J. R. Dubno, et al. (2002). "Recognition of low-pass-filtered consonants in noise with normal and impaired high-frequency hearing." J Acoust Soc Am 111(1 Pt 1): 409-16. F. Husain: See also comment by Strickland et al. 2004, JASA, 116(1) on the above paper. They disagree with Horwitz et al.’s study findings/conclusions. They say “high-CF fibers not necessary for normal speech perception.” 2] From Christian Lorenzi you may have a look at Horwitz et al.'s (very well conducted) work on this topic: Horwitz, A.R., Dubno, J.R. & Ahlstrom, J.B. J. Acoust. Soc. Am. 111, 409-416 (2002). He also sent his ARO 2007 poster on “perception of temporal fine structure cues also reveals the presence of deficits in temporal perception in this low-frequency region”. 3] From Arnaud Norena hearing loss (and the related plastic changes) has been shown to be associated with an improvement of frequency discrimination at the cut-off frequency of the hearing loss (McDermott et al., 1998; Thai-van et al., 2002, 2003, 2007 - in press; Kluk and Moore, 2006). On the other hand, it seems that a hearing loss confined to high frequencies could induce a global increase in auditory hypersensitivity (hyperacusis). We have a paper in press (Norena & Chery-Croze, 2007), but see also the interesting study of Formby et al (2003). 4] From Laurent Demany Lacher-Fougere and Demany (JASA, 2005, 118, page 2519-2526) wrote: "... our data confirm previous evidence (Hawkins and Wightman, 1980; Smoski and Trahiotis, 1986) that, in listeners with bilateral cochlear hearing losses at high frequencies but normal absolute thresholds at low frequencies, the ITD threshold at low frequencies may be abnormally large." (p. 2523). 5] From Emery Ku (I haven’t read this one yet) Harris, FP. Distortion Product Ototacoustic emissions in humans with high frequency sensorineural hearing loss. JSHR, vol 33, 1990. 6] a review article Salvi, RJ et al. Auditory plasticity and hyperactivity following cochlear damage. Hearing Research, vol 147, 2000