Loudness growth in 1/2-octave bands (LGOB)—A procedure for the assessment of loudness

Abstract

In this paper, a method that has been developed for the assessment and quantification of loudness perception in normal-hearing and hearing-impaired persons is described. The method has been named LGOB, which stands for loudness growth in 1/2-octave bands. The method uses 1/2-octave bands of noise, centered at 0.25, 0.5, 1.0, 2.0, and 4.0 kHz, with subjective levels between a subject's threshold of hearing and the "too loud" level. The noise bands are presented to the subject, randomized over frequency and level, and the subject is asked to respond with a loudness rating (one of: VERY SOFT, SOFT, OK, LOUD, VERY LOUD, TOO LOUD). Subject responses (normal and hearing-impaired) are then compared to the average responses of a group of normal-hearing subjects. This procedure allows one to estimate the subject's loudness growth relative to normals, as a function of frequency and level. The results may be displayed either as isoloudness contours or as recruitment curves. In its present form, the measurements take less than 30 min. The signal presentation and analysis is done using a PC and a PC plug-in board having a digital to analog converter.

Loudness Scaling Test Based on Categorical Perception

“…"Classical" loudness scaling tests have several disadvantages (Allen et al, 1990) of which the long time required to obtain the results is the most important one. In addition, test signals (mostly in a form of narrowband noise) are considered as unpleasant.…”

“…For the loudness assessment, the scale of loudness categories is defined according to the particular method. As mentioned before, the LGOB test is an example of such tests (Allen et al, 1990). It is a relatively effective method, that may be easily implemented as a software application.…”

“…A typical test used to detect and measure the abnormal growth of loudness sensation is the binaural alternate loudness balance test (Allen et al, 1990;Hood, 1977). This test assumes that the person tested has one ear healthy (with normal hearing).…”

“…One of the loudness scaling tests, i.e. LGOB (Loudness Growth in 1/2-octave bands) procedure (Allen et al, 1990) used an even simpler scale consisting of seven response alternatives. Another test, named ACALOS (Adaptive Categorical Loudness Scaling) (Brand, 2000;Brand, Hohmann, 2001;2002) was introduced in 2000 and served later as a basis for the new standard ISO 16832 on CLS, i.e.…”

Modeling the Individual Variability of Loudness Perception with a Multi-Category Psychometric Function

“…CLS is a task that has a well-studied relationship with hearing loss, uses category labels that are ecologically valid (e.g., "Loud", "Soft"), can be administered in a clinic relatively quickly (< 5 min/frequency), and requires little training on the part of the tester/listener. For these reasons, this task has been used in a number of loudness studies (Allen et al 1990;Al-Salim et al 2010;Brand and Hohmann 2002;Elberling, 1999;Heeren et al 2013).…”