Temporal integration functions of amplitude modulation detection and amplitude modulation depth discrimination

2005 ◽  
Vol 117 (4) ◽  
pp. 2535-2535
Author(s):  
Jungmee Lee ◽  
Glenis Long
Keyword(s):  
Amplitude Modulation ◽  
Modulation Depth ◽  
Temporal Integration ◽  
Depth Discrimination ◽  
Modulation Detection

scholarly journals Contribution of onset/offset information of modulation to amplitude modulation depth discrimination

2008 ◽  
Vol 123 (5) ◽  
pp. EL111-EL115 ◽  
Author(s):  
Derek R. Edwards ◽  
Jungmee Lee ◽  
Jennifer Andrews ◽  
Aileen Wong
Keyword(s):  
Amplitude Modulation ◽  
Modulation Depth ◽  
Depth Discrimination

scholarly journals Association of Auditory Steady State Responses with Perception of Temporal Modulations and Speech in Noise

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Venugopal Manju ◽  
Kizhakke Kodiyath Gopika ◽  
Pitchai Muthu Arivudai Nambi
Keyword(s):  
Steady State ◽  
Speech Perception ◽  
Amplitude Modulation ◽  
Modulation Depth ◽  
Normal Hearing ◽  
Positive Correlation ◽  
Behavioral Method ◽  
Modulation Detection ◽  
Auditory Steady State Responses ◽  
40 Hz

Amplitude modulations in the speech convey important acoustic information for speech perception. Auditory steady state response (ASSR) is thought to be physiological correlate of amplitude modulation perception. Limited research is available exploring association between ASSR and modulation detection ability as well as speech perception. Correlation of modulation detection thresholds (MDT) and speech perception in noise with ASSR was investigated in twofold experiments. 30 normal hearing individuals and 11 normal hearing individuals within age range of 18–24 years participated in experiments 1 and 2, respectively. MDTs were measured using ASSR and behavioral method at 60 Hz, 80 Hz, and 120 Hz modulation frequencies in the first experiment. ASSR threshold was obtained by estimating the minimum modulation depth required to elicit ASSR (ASSR-MDT). There was a positive correlation between behavioral MDT and ASSR-MDT at all modulation frequencies. In the second experiment, ASSR for amplitude modulation (AM) sweeps at four different frequency ranges (30–40 Hz, 40–50 Hz, 50–60 Hz, and 60–70 Hz) was recorded. Speech recognition threshold in noise (SRTn) was estimated using staircase procedure. There was a positive correlation between amplitude of ASSR for AM sweep with frequency range of 30–40 Hz and SRTn. Results of the current study suggest that ASSR provides substantial information about temporal modulation and speech perception.

scholarly journals Amplitude modulation depth discrimination in hearing‐impaired and normal‐hearing listeners

2008 ◽  
Vol 123 (5) ◽  
pp. 3859-3859
Author(s):  
Stephan D. Ewert ◽  
Jutta Volmer ◽  
Torsten Dau ◽  
Jesko Verhey
Keyword(s):  
Amplitude Modulation ◽  
Modulation Depth ◽  
Normal Hearing ◽  
Hearing Impaired ◽  
Depth Discrimination

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.

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