Journal of The Acoustical Society of America, 2002
Ira Hirsh's contributions to clinical science and research are diverse and significant. In fa... more Ira Hirsh's contributions to clinical science and research are diverse and significant. In fact, approximately one-third of the 100+ publications that Ira lists in his curriculum vitae (CV) are clinical in nature, dealing with various aspects of audiology, deafness, hearing aids, aural rehabilitation, and speech and language pathology. The majority of these citations, fully one-quarter of his publication list, addresses
The Journal of the Acoustical Society of America, 1994
The temporal envelope detector [N. Viemeister, J. Acoust. Soc. Am. 66, 1364–1380 (1979)] is a goo... more The temporal envelope detector [N. Viemeister, J. Acoust. Soc. Am. 66, 1364–1380 (1979)] is a good single-channel model for auditory temporal processing. The model has three stages: (1) an initial bandpass filter, followed serially by (2) a nonlinear element, and (3) a lowpass filter. A digital version of the model using a max–min decision rule [Forrest and Green, J. Acoust. Soc. Am. 82, 1933–1943 (1987)] at the model’s output has been used to simulate temporal gap detection (TGD) thresholds for silent temporal gaps in pairs of sinusoidal markers (F1 and F2). Simulated TGD thresholds were measured as a function of marker frequency separation in the same manner as described in psychophysical experiments [Formby et al., companion paper at this meeting]. Simulated TGD thresholds depended directly on marker frequency separation. For a given frequency separation, simulated TGD thresholds were minimized by centering the symmetrical, first-stage roex filter between the two marker frequenci...
The Journal of the Acoustical Society of America, 2003
Strategies for treating hyperacusis, an anomolous condition of loudness perception, paradoxically... more Strategies for treating hyperacusis, an anomolous condition of loudness perception, paradoxically seek either to minimize or enhance listeners’ sound exposures. We show that these reciprocal treatment approaches, implemented with similar amounts of background sound attenuation and enhancement, produce diametrically opposite perceptual effects in normal listeners. Specifically, we show after continuous, 2-week earplugging and low-level noise treatments that listeners become more and less sensitive, respectively, to the loudness of sounds. This simple demonstration of adaptive plasticity is consistent with modification of a theoretical gain control process, which is the basis for desensitizing sound therapies used in treating hyperacusis and related sound tolerance problems.
The Journal of the Acoustical Society of America, 1998
Complex temporal patterns of under- and over-shoot (i.e., enhanced and diminished detection) at o... more Complex temporal patterns of under- and over-shoot (i.e., enhanced and diminished detection) at onset and offset of a 200-ms, 400-Hz-wide noise masker (2500 Hz center frequency) have been reported for a temporal masking paradigm [Formby et al.., J. Acoust. Soc. Am. 102, 3161(A) (1997)]. The paradigm measured detection of a 5-ms sinusoidal signal (1900 or 2100 Hz) at 43 temporal positions preceding, during, and following the masker. Efforts to model under- and over-shoot patterns in the temporal masking functions will be considered. The modeling strategy is similar to that used in the study of vestibular adaptation [Formby et al., 21st Meeting of Association for Research in Otolaryngology, 1988], and allows for quantification of the relative amplitudes, time constants, and delays of excitatory and adaptive processes. Linear combinations of exponential functions are used to represent the effects of excitatory masking and adaptation. Suppression and adaptation of suppression may also p...
Journal of Speech, Language, and Hearing Research, 2002
Classical temporal integration (TI) is often viewed as a frequency-dependent, energy-based detect... more Classical temporal integration (TI) is often viewed as a frequency-dependent, energy-based detection process. Detection thresholds for brief sinusoidal increments in either a fixed-level or a random-level broadband pedestal are reported that refute this traditional perspective of TI. Instead, evidence is presented that indicates (a) detection of absolute energy is not necessary for the TI effect and (b) the frequency dependence of TI is consistent with variations across frequency in peripheral auditory tuning, rather than the integration process per se. When peripheral frequency selectivity is controlled, TI can be explained by a frequencyinvariant integration process over at least the frequency range from 500 to 4000 Hz. This process is characterized by threshold improvements of 8–9 dB per decade increase in duration for increment durations between 10 and 300 ms.
Positron emission tomography (PET) was used to map alterations in local neuronal activity induced... more Positron emission tomography (PET) was used to map alterations in local neuronal activity induced in human primary auditory cortex by pure-tone stimulation. Patterns of blood flow were observed in specific regions on the superior temporal plane showing systematic changes in activity depending on the frequency of a stimulating pure tone. The orientation of these regions agrees well with data for non-human primates.
Journal of The Acoustical Society of America, 2002
Ira Hirsh's contributions to clinical science and research are diverse and significant. In fa... more Ira Hirsh's contributions to clinical science and research are diverse and significant. In fact, approximately one-third of the 100+ publications that Ira lists in his curriculum vitae (CV) are clinical in nature, dealing with various aspects of audiology, deafness, hearing aids, aural rehabilitation, and speech and language pathology. The majority of these citations, fully one-quarter of his publication list, addresses
The Journal of the Acoustical Society of America, 1994
The temporal envelope detector [N. Viemeister, J. Acoust. Soc. Am. 66, 1364–1380 (1979)] is a goo... more The temporal envelope detector [N. Viemeister, J. Acoust. Soc. Am. 66, 1364–1380 (1979)] is a good single-channel model for auditory temporal processing. The model has three stages: (1) an initial bandpass filter, followed serially by (2) a nonlinear element, and (3) a lowpass filter. A digital version of the model using a max–min decision rule [Forrest and Green, J. Acoust. Soc. Am. 82, 1933–1943 (1987)] at the model’s output has been used to simulate temporal gap detection (TGD) thresholds for silent temporal gaps in pairs of sinusoidal markers (F1 and F2). Simulated TGD thresholds were measured as a function of marker frequency separation in the same manner as described in psychophysical experiments [Formby et al., companion paper at this meeting]. Simulated TGD thresholds depended directly on marker frequency separation. For a given frequency separation, simulated TGD thresholds were minimized by centering the symmetrical, first-stage roex filter between the two marker frequenci...
The Journal of the Acoustical Society of America, 2003
Strategies for treating hyperacusis, an anomolous condition of loudness perception, paradoxically... more Strategies for treating hyperacusis, an anomolous condition of loudness perception, paradoxically seek either to minimize or enhance listeners’ sound exposures. We show that these reciprocal treatment approaches, implemented with similar amounts of background sound attenuation and enhancement, produce diametrically opposite perceptual effects in normal listeners. Specifically, we show after continuous, 2-week earplugging and low-level noise treatments that listeners become more and less sensitive, respectively, to the loudness of sounds. This simple demonstration of adaptive plasticity is consistent with modification of a theoretical gain control process, which is the basis for desensitizing sound therapies used in treating hyperacusis and related sound tolerance problems.
The Journal of the Acoustical Society of America, 1998
Complex temporal patterns of under- and over-shoot (i.e., enhanced and diminished detection) at o... more Complex temporal patterns of under- and over-shoot (i.e., enhanced and diminished detection) at onset and offset of a 200-ms, 400-Hz-wide noise masker (2500 Hz center frequency) have been reported for a temporal masking paradigm [Formby et al.., J. Acoust. Soc. Am. 102, 3161(A) (1997)]. The paradigm measured detection of a 5-ms sinusoidal signal (1900 or 2100 Hz) at 43 temporal positions preceding, during, and following the masker. Efforts to model under- and over-shoot patterns in the temporal masking functions will be considered. The modeling strategy is similar to that used in the study of vestibular adaptation [Formby et al., 21st Meeting of Association for Research in Otolaryngology, 1988], and allows for quantification of the relative amplitudes, time constants, and delays of excitatory and adaptive processes. Linear combinations of exponential functions are used to represent the effects of excitatory masking and adaptation. Suppression and adaptation of suppression may also p...
Journal of Speech, Language, and Hearing Research, 2002
Classical temporal integration (TI) is often viewed as a frequency-dependent, energy-based detect... more Classical temporal integration (TI) is often viewed as a frequency-dependent, energy-based detection process. Detection thresholds for brief sinusoidal increments in either a fixed-level or a random-level broadband pedestal are reported that refute this traditional perspective of TI. Instead, evidence is presented that indicates (a) detection of absolute energy is not necessary for the TI effect and (b) the frequency dependence of TI is consistent with variations across frequency in peripheral auditory tuning, rather than the integration process per se. When peripheral frequency selectivity is controlled, TI can be explained by a frequencyinvariant integration process over at least the frequency range from 500 to 4000 Hz. This process is characterized by threshold improvements of 8–9 dB per decade increase in duration for increment durations between 10 and 300 ms.
Positron emission tomography (PET) was used to map alterations in local neuronal activity induced... more Positron emission tomography (PET) was used to map alterations in local neuronal activity induced in human primary auditory cortex by pure-tone stimulation. Patterns of blood flow were observed in specific regions on the superior temporal plane showing systematic changes in activity depending on the frequency of a stimulating pure tone. The orientation of these regions agrees well with data for non-human primates.
Uploads
Papers by Charles Formby