Loudness recruitment: Contributing mechanisms as revealed by cochlear AP measures in man
A measure of the (average) rate of discharge versus intensity function of cochlear fibers can be obtained from cochlear-evoked compound action potentials using a tone-on-tone forward masking technique. The rationale for the method is presented. This technique was used to investigate, indirectly, cochlear fiber responses in human subjects, both with normal hearing and with deafness of cochlear origin and showing signs of loudness recruitment. In animals with pathologic cochleas, the change in rate of fiber discharge with intensity is more rapid than in normal animals. The present study confirms that this also is the case in human cochlear pathology and suggests that this abnormal steepening of rate versus intensity functions contributes to the phenomenon of loudness recruitment.
Key wordsLoudness recruitment Cochlear pathology Cochlear nerve fibers Intensity functions
Unable to display preview. Download preview PDF.
- 2.Aran J-M, Portmann CL, Delaunay J, Pelerin J, Lenoir J (1969) L'electrocochleogramme: methodes et premiers résultats chez l'enfant. Rev Laryngol Otol Rhinol (Bord) 90: 615–634Google Scholar
- 11.Harrison RV, Evans EF (1977) The effect of hair cell loss (restricted to outer hair cells) on the threshold and tuning properties of cochlear fibres in the guinea pig. In: Portmann M, Aran J-M (eds) Inner ear biology, Coll INSERM 68. INSERM, Paris, pp 105–124Google Scholar
- 12.Harrison RV, Evans EF (1979) Cochlear fibre responses in guinea pigs with well defined cochlear lesions. Scand Audiol [Suppl] 9: 83–92Google Scholar
- 15.Hoekstra A, Ritsma RJ (1977) Perceptive hearing loss and frequency selectivity. In: Evans EF, Wilson JP (eds) Psychophysics and physiology of hearing. Academic Press, London, pp 283–292Google Scholar
- 16.Kiang NYS, Moxon EC, Levine RA (1970) Auditory nerve activity in cats with normal and abnormal cochleas. In: Wolstenholme GEW, Knight J (eds) Sensorineural hearing loss. Churchill, London, pp 241–268Google Scholar
- 17.Leshowitz B, Lindstrom R (1977) Measurement of nonlinearities in listeners with sensorineural hearing loss. In: Evans EF, Wilson JP (eds) Psychophysics and physiology of hearing. Academic Press, London, pp 283–292Google Scholar
- 18.Pick GF, Evans EF, Wilson JP (1977) Frequency resolution of patients with hearing loss of cochlear origin. In: Evans EF, Wilson JP (eds) Psychophysics and physiology of hearing. Academic Press, London, pp 273–281Google Scholar
- 23.Wightman F, McGee T, Kramer M (1977) Factors influencing frequency selectivity in normal and hearing impaired listeners. In: Evans EF, Wilson JP (eds) Psychophysics and physiology of hearing. Academic Press, London, pp 295–306Google Scholar