The effect of aging on horizontal plane sound localization

Abstract

An experiment was conducted to determine the effect of aging on sound localization. Seven groups of 16 subjects, aged 10-81 years, were tested. Sound localization was assessed using six different arrays of four or eight loudspeakers that surrounded the subject in the horizontal plane, at a distance of 1 m. For two 4-speaker arrays, one loudspeaker was positioned in each spatial quadrant, on either side of the midline or the interaural axis, respectively. For four 8-speaker arrays, two loudspeakers were positioned in each quadrant, one close to the midline and the second separated from the first by 15 degrees, 30 degrees, 45 degrees, or 60 degrees. Three different 300-ms stimuli were localized: two one-third-octave noise bands, centered at 0.5 and 4 kHz, and broadband noise. The stimulus level (75 dB SPL) was well above hearing threshold for all subjects tested. Over the age range studied, percent-correct sound-source identification judgments decreased by 12%-15%. Performance decrements were apparent as early as the third decade of life. Broadband noise was easiest to localize (both binaural and spectral cues were available), and the 0.5-kHz noise band, the most difficult to localize (primarily interaural temporal difference cue available). Accuracy was relatively higher in front of than behind the head, and errors were largely front/back mirror image reversals. A left-sided superiority was evident until the fifth decade of life. The results support the conclusions that the processing of spectral information becomes progressively less efficient with aging, and is generally worse for sources on the right side of space.

Effects of sex and age on auditory spatial scene analysis

“…The lack of an age effect for single-sound localization may be explained by relatively low task difficulty, and the fact that the older group included mainly middle-aged subjects. In seeming opposition to this, Abel et al (2000) have shown that correct single-source identification judgments decreased as early as in the third decade of life. However, the proportion of correct identifications analysed by these authors may involve factors different from the constant error used here as a measure of performance.…”

“…However, the proportion of correct identifications analysed by these authors may involve factors different from the constant error used here as a measure of performance. Also, an anechoic environment was used here, while the experiments of Abel et al (2000) were conducted in a semireverberant environment, thus involving phenomena such as echo suppression (Cranford et al, 1990). Because echoes could have been distracting, the approach of Abel et al (2000) may be comparable with the present distractor-sound condition, in which deterioration in performance was obtained at middle age (cf.…”

“…Also, an anechoic environment was used here, while the experiments of Abel et al (2000) were conducted in a semireverberant environment, thus involving phenomena such as echo suppression (Cranford et al, 1990). Because echoes could have been distracting, the approach of Abel et al (2000) may be comparable with the present distractor-sound condition, in which deterioration in performance was obtained at middle age (cf. Lee et al, 2009;Litovsky and Shinn-Cunningham, 2001).…”

“…If so, the asymmetry should be interpreted in terms of higher-order spatial attention. Studies using young adults that employed audiospatial tasks with single sound sources have revealed a left-hemispace advantage, e.g., for localization (Abel et al, 2000;Burke et al, 1994) or motion perception (Hirnstein et al, 2007). Such asymmetries have been related to the superiority of the right cortical hemisphere in auditory spatial processing (Griffiths et al, 1998;Kaiser et al, 2000;Kreitewolf et al, 2011).…”

“…Finally, this experiment was conducted under ideal acoustical conditions of an anechoic environment. In addition, left/right asymmetries in localization performance were analysed, as these have been found for single target sound sources (Abel et al, 2000;Ocklenburg et al, 2010).…”