The notched-noise method directly measures auditory filter shape.

Evidence

Patterson (1976) developed the notchednoise method to measure the shape of the auditory filter. This method uses a masker that is two bands of noise (~300-Hz wide or so) with a spectral notch placed between them. The tone to be detected (the signal) has a frequency that falls within the spectral notch. Rather than vary the bandwidth of the noise like Fletcher did, the bandwidth of the spectral notch is varied. Larger notches will lead to less masking compared with smaller notches, due to fewer masking components falling within the theoretical auditory filter surrounding the signal frequency. One advantage of this method is that asymmetrical placement of the notch around the center frequency can allow measurement of a filter that is asymmetrical. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 490

The auditory filter can be calculated by applying the power spectrum model of masking to estimate the shape and characteristics of the auditory filter. To estimate the auditory filter, one must make some initial assumptions about the auditory filter, such as an approximation of the shape and size of the filter. We then pass the stimuli through this hypothetical filter, and using the power at the output of the filter, estimate the signal level at threshold for various notch bandwidths. By comparing the predicted data with the actual obtained data, we can revise the parameters selected for the auditory filter. When the predicted data yield a good match to the obtained data, we have an estimate of the auditory filter. Parameters that are commonly estimated are the bandwidth of the filter and the slope of the highand lowfrequency skirts. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 493

The auditory filter can be calculated by applying the power spectrum model of masking to estimate the shape and characteristics of the auditory filter. To estimate the auditory filter, one must make some initial assumptions about the auditory filter, such as an approximation of the shape and size of the filter. We then pass the stimuli through this hypothetical filter, and using the power at the output of the filter, estimate the signal level at threshold for various notch bandwidths. By comparing the predicted data with the actual obtained data, we can revise the parameters selected for the auditory filter. When the predicted data yield a good match to the obtained data, we have an estimate of the auditory filter. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 493

Categorization

• DEFINE: Explains the notched-noise method for estimating auditory filter shape, a key technique.
• XREF: Connects to the reader’s ongoing interest in auditory filtering models and how they differ between normal and impaired hearing. — connects to: Psychoacoustic tuning curves directly reflect cochlear mechanical processing. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 223; The auditory filter width is what matters for sound and voice technology design.; Off-frequency listening can distort auditory filter measurement unless masked (+1 more)
• corroborated: 5 independent passages support this claim — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 490; Jennifer Lentz, Psychoacoustics- Perception of Normal…, 493