scholarly journals Methods for expressing spectral modulation depth and the effects of modulator shape on spectral modulation detection thresholds

2019 ◽  
Author(s):  
Sittiprapa Isarangura ◽  
Katherine N. Palandrani ◽  
Trevor Stavropoulos ◽  
Aaron Seitz ◽  
Eric C. Hoover ◽  
...  
Keyword(s):  
Modulation Depth ◽  
Detection Thresholds ◽  
Spectral Modulation ◽  
Modulation Detection

The effects of modulator shape and methods for expressing modulation depth on spectral modulation detection thresholds

2019 ◽  
Vol 145 (3) ◽  
pp. 1722-1722 ◽  
Author(s):  
Sittiprapa Isarangura ◽  
Katherine Palandrani ◽  
Trevor Stavropoulos ◽  
Aaron Seitz ◽  
Eric C. Hoover ◽  
...  
Keyword(s):  
Modulation Depth ◽  
Detection Thresholds ◽  
Spectral Modulation ◽  
Modulation Detection

scholarly journals How Do Age and Hearing Loss Impact Spectral Envelope Perception?

2018 ◽  
Vol 61 (9) ◽  
pp. 2376-2385 ◽  
Author(s):  
Erol J. Ozmeral ◽  
Ann C. Eddins ◽  
David A. Eddins
Keyword(s):  
Hearing Loss ◽  
Spectral Resolution ◽  
Modulation Frequency ◽  
Normal Hearing ◽  
Frequency Resolution ◽  
Spectral Envelope ◽  
Detection Thresholds ◽  
Spectral Modulation ◽  
Modulation Detection ◽  
Moderate Hearing Loss

Purpose The goal was to evaluate the potential effects of increasing hearing loss and advancing age on spectral envelope perception. Method Spectral modulation detection was measured as a function of spectral modulation frequency from 0.5 to 8.0 cycles/octave. The spectral modulation task involved discrimination of a noise carrier (3 octaves wide from 400 to 3200 Hz) with a flat spectral envelope from a noise having a sinusoidal spectral envelope across a logarithmic audio frequency scale. Spectral modulation transfer functions (SMTFs; modulation threshold vs. modulation frequency) were computed and compared 4 listener groups: young normal hearing, older normal hearing, older with mild hearing loss, and older with moderate hearing loss. Estimates of the internal spectral contrast were obtained by computing excitation patterns. Results SMTFs for young listeners with normal hearing were bandpass with a minimum modulation detection threshold at 2 cycles/octave, and older listeners with normal hearing were remarkably similar to those of the young listeners. SMTFs for older listeners with mild and moderate hearing loss had a low-pass rather than a bandpass shape. Excitation patterns revealed that limited spectral resolution dictated modulation detection thresholds at high but not low spectral modulation frequencies. Even when factoring out (presumed) differences in frequency resolution among groups, the spectral envelope perception was worse for the group with moderate hearing loss than the other 3 groups. Conclusions The spectral envelope perception as measured by spectral modulation detection thresholds is compromised by hearing loss at higher spectral modulation frequencies, consistent with predictions of reduced spectral resolution known to accompany sensorineural hearing loss. Spectral envelope perception is not negatively impacted by advancing age at any spectral modulation frequency between 0.5 and 8.0 cycles/octave.

scholarly journals The Effects of Duration and Level on Spectral Modulation Perception

2019 ◽  
Vol 62 (10) ◽  
pp. 3876-3886 ◽  
Author(s):  
Sittiprapa Isarangura ◽  
Ann C. Eddins ◽  
Erol J. Ozmeral ◽  
David A. Eddins
Keyword(s):  
Speech Perception ◽  
Stimulus Duration ◽  
Auditory Perception ◽  
Standard Stimulus ◽  
Modulation Frequency ◽  
Plain Language ◽  
Detection Thresholds ◽  
Spectral Modulation ◽  
Presentation Level ◽  
Modulation Detection

Purpose Spectral modulation detection is an increasingly common assay of suprathreshold auditory perception and has been correlated with speech perception performance. Here, the potential effects of stimulus duration and stimulus presentation level on spectral modulation detection were investigated. Method Spectral modulation detection thresholds were measured as a function of modulation frequency in young, normal-hearing listeners. The standard stimulus was a bandpass noise, and signal stimuli were created by superimposing sinusoidal spectral modulation on the bandpass noise carrier. The modulation was sinusoidal on a log 2 frequency axis and a log 10 (dB) amplitude scale with a random starting phase (0–2π radians). In 1 experiment, stimulus durations were 50, 100, 200, or 400 ms (at fixed level 81 dB SPL). In a 2nd experiment, stimuli were presented at sensation levels of 10, 20, 30, 40, and 60 dB SL (fixed at a duration of 400 ms). Results Spectral modulation detection thresholds were similarly low for the 400- and 200-ms durations, increased slightly for the 100-ms duration, and increased markedly for the 50-ms duration. Thresholds were lowest for 40 dB SL; increased slightly for 20, 30, and 60 dB SL; and markedly higher for the 10–dB SL condition. Conclusions The increase in thresholds for the shortest durations and lowest sensational levels is consistent with previous investigations of auditory spectral profile analysis. The effects of presentation level and stimulus duration are important considerations in the context of understanding potential relationships between the perception of spectral cues and speech perception, when designing investigations and interpreting data related to spectral envelope perception, and in the context of models of auditory perception. As examples, 2 simple models based on auditory nerve output that have been used to explain spectrotemporal modulation in previous investigations produced an output inconsistent with the present results. Plain language summary Intensity variations across audio frequency lead to spectral shapes that are essential and sometimes signature features of various sounds in the environment, including speech. Here, we show how laboratory measures of spectral shape perception depend on presentation level and stimulus duration.

scholarly journals Ability of primary auditory cortical neurons to detect amplitude modulation with rate and temporal codes: neurometric analysis

2012 ◽  
Vol 107 (12) ◽  
pp. 3325-3341 ◽  
Author(s):  
Jeffrey S. Johnson ◽  
Pingbo Yin ◽  
Kevin N. O'Connor ◽  
Mitchell L. Sutter
Keyword(s):  
Amplitude Modulation ◽  
Cortical Neurons ◽  
Modulation Depth ◽  
Modulation Frequency ◽  
Primary Auditory Cortex ◽  
Detection Methods ◽  
Lower Envelope ◽  
Detection Thresholds ◽  
Modulation Detection ◽  
Temporal Measures

Amplitude modulation (AM) is a common feature of natural sounds, and its detection is biologically important. Even though most sounds are not fully modulated, the majority of physiological studies have focused on fully modulated (100% modulation depth) sounds. We presented AM noise at a range of modulation depths to awake macaque monkeys while recording from neurons in primary auditory cortex (A1). The ability of neurons to detect partial AM with rate and temporal codes was assessed with signal detection methods. On average, single-cell synchrony was as or more sensitive than spike count in modulation detection. Cells are less sensitive to modulation depth if tested away from their best modulation frequency, particularly for temporal measures. Mean neural modulation detection thresholds in A1 are not as sensitive as behavioral thresholds, but with phase locking the most sensitive neurons are more sensitive, suggesting that for temporal measures the lower-envelope principle cannot account for thresholds. Three methods of preanalysis pooling of spike trains (multiunit, similar to convergence from a cortical column; within cell, similar to convergence of cells with matched response properties; across cell, similar to indiscriminate convergence of cells) all result in an increase in neural sensitivity to modulation depth for both temporal and rate codes. For the across-cell method, pooling of a few dozen cells can result in detection thresholds that approximate those of the behaving animal. With synchrony measures, indiscriminate pooling results in sensitive detection of modulation frequencies between 20 and 60 Hz, suggesting that differences in AM response phase are minor in A1.

scholarly journals Effect of current focusing on the sensitivity of inferior colliculus neurons to amplitude-modulated stimulation

2016 ◽  
Vol 116 (3) ◽  
pp. 1104-1116 ◽  
Author(s):  
Shefin S. George ◽  
Mohit N. Shivdasani ◽  
James B. Fallon
Keyword(s):  
Inferior Colliculus ◽  
Cochlear Implants ◽  
Modulation Depth ◽  
Neural Activation ◽  
Detection Thresholds ◽  
P Values ◽  
Pulse Trains ◽  
Spectral Cues ◽  
Current Focusing ◽  
Channel Interactions

In multichannel cochlear implants (CIs), current is delivered to specific electrodes along the cochlea in the form of amplitude-modulated pulse trains, to convey temporal and spectral cues. Our previous studies have shown that focused multipolar (FMP) and tripolar (TP) stimulation produce more restricted neural activation and reduced channel interactions in the inferior colliculus (IC) compared with traditional monopolar (MP) stimulation, suggesting that focusing of stimulation could produce better transmission of spectral information. The present study explored the capability of IC neurons to detect modulated CI stimulation with FMP and TP stimulation compared with MP stimulation. The study examined multiunit responses of IC neurons in acutely deafened guinea pigs by systematically varying the stimulation configuration, modulation depth, and stimulation level. Stimuli were sinusoidal amplitude-modulated pulse trains (carrier rate of 120 pulses/s). Modulation sensitivity was quantified by measuring modulation detection thresholds (MDTs), defined as the lowest modulation depth required to differentiate the response of a modulated stimulus from an unmodulated one. Whereas MP stimulation showed significantly lower MDTs than FMP and TP stimulation ( P values <0.05) at stimulation ≤2 dB above threshold, all stimulation configurations were found to have similar modulation sensitivities at 4 dB above threshold. There was no difference found in modulation sensitivity between FMP and TP stimulation. The present study demonstrates that current focusing techniques such as FMP and TP can adequately convey amplitude modulation and are comparable to MP stimulation, especially at higher stimulation levels, although there may be some trade-off between spectral and temporal fidelity with current focusing stimulation.

Modulation detection thresholds for cochlear implants: Dependence on stimulation site and stimulus level

2006 ◽  
Vol 120 (5) ◽  
pp. 3342-3342 ◽  
Author(s):  
Bryan E. Pfingst ◽  
Rose A. Burkholder ◽  
Catherine S. Thompson ◽  
Li Xu
Keyword(s):  
Cochlear Implants ◽  
Stimulus Level ◽  
Stimulation Site ◽  
Detection Thresholds ◽  
Modulation Detection

Spectral modulation detection training in older adults with hearing loss.

2009 ◽  
Vol 125 (4) ◽  
pp. 2633-2633
Author(s):  
Andrew T. Sabin ◽  
Cynthia A. Clark ◽  
David A. Eddins ◽  
Sumitrajit Dhar ◽  
Beverly A. Wright
Keyword(s):  
Older Adults ◽  
Hearing Loss ◽  
Spectral Modulation ◽  
Modulation Detection
Sign in / Sign up

Export Citation Format

Share Document