Assessment of Speech Perception in Elderly Using Speech Auditory Brainstem Response (S) ABR

Background: The speech auditory brainstem response is a tool that provides direct information on how speech sound is temporally and spectrally coded by the auditory brainstem. Speech auditory brainstem response is influenced by many variables, but the effect of gender is unclear, particularly in the binaural recording. Studies on speech auditory brainstem response evoked by binaural stimulation are limited, but gender studies are even more limited and contradictory. This study aimed at examining the effect of gender on speech auditory brainstem response in adults.Methods: Time- and frequency-domain analyses of speech auditory brainstem response recordings of 30 healthy participants (15 women and 15 men) aged 18-35 years with normal hearing and no musical education were obtained. For each adult, speech auditory brainstem response was recorded with the syllable /da/ presented binaurally. Peaks of time (V, A, C, D, E, F, and O) and frequency (fundamental frequency, first formant frequency, and high frequency) domains of speech auditory brainstem response were compared between men and women.Results: V, A, and F peak latencies of women were significantly shorter than those of men (P < .05). However, no difference was found in the peak amplitude of the time (P > .05) or frequency domain between women and men (P > .05).Conclusion: Gender differences in binaural speech auditory brainstem response are significant in adults, particularly in the time domain. When speech stimuli are used for auditory brainstem responses, normative data specific to gender are required. Preliminary normative data from this study could serve as a reference for future studies on binaural speech auditory brainstem response among Turkish adults.

Exploration électrophysiologique des voies auditives sous-corticales chez l’humain : du clic au son de parole

Introduction: Subjects using hearing aids complains of difficulty in speech understanding in noise. Speech auditory brainstem response (S-ABR) provides cues for temporal and spectral encoding of speech in the brainstem.Objective: This work was designed to evaluate speech processing in patients fitted with hearing aid using S-ABR and to study the effect of noise reduction algorithm on speech processing in patients fitted with hearing aids.Materials and method: This study included 20 adults with mild to severe SNHL fitted with HA at least 3 months with aided threshold in all frequencies better than or equal to 30 dB. Hearing aid was used with all the subjects and was programed for each subject according to his audiogram followed by aided evaluation using S-ABR. Through sound field in four different test conditions with NR algorithm on in quiet and in the presence of noise then with the NR off in quiet and in the presence of noise were performed.Results: There was a statistically significant delay in the S-ABR onset and offset in noise compared to quiet. The effect of noise on S-ABR while the NR was on showed statistically significant difference in the onset response in both quiet and noise. When the NR was off, there was marked effect of noise on both the onset response and offset response.Conclusions: It was found that hearing aid users are vulnerable to noise regarding the speech encoding at the level of the brainstem. Noise reduction algorithm maintains the neural activity in response to speech and improves speech perception in noise.

Through a systematic literature review, this paper evaluates the clinical applicability of speech-evoked auditory brainstem responses (ABRs). The survey was done on five databases, with the following key words: speech ABR; ABR-speech; speech auditory brainstem response; auditory evoked potential to speech; speech-evoked brainstem response; complex sounds; and cABR. The search generated a list of 1288 items published between 2005 and 2015. After applying pre-established criteria of inclusion and exclusion, 21 publications remained. The collected data show that: (i) research on speech ABR has been done on diverse age groups, although teenagers and adolescents have been less studied; (ii) the speech ABR procedure has been shown to be a reliable and effective tool in evaluating the coding of speech sounds in the brainstem, and can also be applied to young children; and (iii) speech ABR has been shown to be effective in the differential diagnosis of diseases with similar features and symptoms.

Learning to Encode Timing: Mechanisms of Plasticity in the Auditory Brainstem

Introduction Speech-evoked auditory brainstem response (ABR) has been used to assess the fidelity of encoding speech stimuli at the subcortical level in normal individuals in noise and in special populations such as learning-impaired children and musicians. The neural code generated by cochlear implants (CIs) in the auditory brainstem pathway and its similarity to stimulus may account for variable speech development in cochlear implantees. Objective The aim of this study was to describe speech ABR recorded in CI individuals and establish measurement parameters for the neural response and its reproducibility. Participants and methods Children between 5 and 10 years of age implanted in the right ear with fully inserted 12-electrode CIs were selected. All participants had normal morphology of the cochlea and auditory nerve in preoperative computed tomographic scan and MRI. Speech syllable 40 ms /da/ was used to elicit speech ABR. Response traces for intensity input/output functions were harvested. Grand averages were constructed for peak picking. Individual patient responses were analyzed for reproducibility, latency of wave V, root mean square amplitude of the response, and correlation to the stimulus. Results Grand averages showed wave V, followed by the frequency following response. Wave V is a vertex-positive peak, equivalent to that elicited by a click, which reflects the stimulation by the transient /d/. The mean latency of wave V was 2.59±0.7 ms at 70 dBHL. The frequency following response showed multiple sequenced troughs corresponding to the sustained vowel /a/. Individual responses collected for similar stimulus parameters showed high reproducibility, being 99.65% at 60 dBHL and 52.8% at 30 dBHL. Participants showed variable latency and root mean square amplitude-intensity input–output functions slopes. The mean stimulus-to-response correlation was 18.1±3.1%. Conclusion Speech ABR in CI participants shows similar morphology to that recorded in norms. CIs thus transcribe the speech signal with high fidelity to the brainstem pathways.

Objective We aimed to study the effect of background noise on speech auditory evoked responses in both normal-hearing (NH) individuals and those with sensorineural hearing loss (SNHL) and correlate these neurophysiological results with subjective measures. Background Understanding speech in noisy situations is one of the most complex activities encountered in everyday life. It is dependent on cognitive factors and sound processing at peripheral, subcortical, and cortical levels. These make perception of speech in noise one of the most complex aspects of human communication. Patients and methods Fifty NH individuals and 40 individuals with mild-to-moderate SNHL were subjected to the Speech, Spatial, and Qualities of Hearing Scale questionnaire, the speech perception in noise test, speech auditory brainstem response, and cortical auditory evoked responses using speech syllable/da/in quiet condition and at three different signal-to-noise ratios (SNRs) (+10, 0, and − 10). Results Speech auditory brainstem response results in NH participants showed delayed latencies of both transients (waves V, A, C, and O) and frequency-following response with reduction in amplitudes of onset (V and A) and F wave only in noisy relative to quiet condition, whereas in SNHL delayed latencies and decreased amplitudes of both transients and fractional flow reserve (FFR) were observed. The effect of noise can be seen in all waves of cortical auditory evoked responses – that is, with decreasing SNR response, latency increased and response amplitude decreased in both SNHL and NH. Conclusion Background noise affects both transients and sustained components of speech in NH and SNHL. P1, N1, P2, and N2 components are all affected by SNR, despite their distinct neural generators; this raises the possibility that the effects demonstrated here are reflective of subcortical processing that is propagated to higher levels of the auditory system. cocktail party, speech auditory brainstem response, speech-in-noise perception

It is commonly assumed that difficulty in listening to speech in noise is at least partly due to deficits in neural temporal processing. Given that noise reduces the temporal fidelity of the auditory brainstem response (ABR) to speech, it has been suggested that the speech ABR may serve as an index of such neural deficits. However, the temporal fidelity of ABRs, to both speech and non-speech sounds, is also known to be influenced by the cochlear origin of the response, as responses from higher-frequency cochlear regions are faster and more synchronous than responses from lower-frequency regions. Thus, if noise caused a reweighting of response contributions from higher- to lower-frequency cochlear regions, the temporal fidelity of the aggregate response should be reduced even in the absence of any changes in neural processing. This ‘place mechanism’ has been demonstrated for non-speech ABRs. The aim of this study was to test whether it also applies to speech ABRs. We used the so-called ‘derived-band’ method to isolate response contributions from frequency-limited cochlear regions. Broadband and derived-band speech ABRs were measured both in quiet and in noise. Whilst the noise caused significant changes to the temporal properties of the broadband response, its effects on the derived-band responses were mostly restricted to the response amplitudes. Importantly, the amplitudes of the higher-frequency derived-band responses were much more strongly affected than those of the lower-frequency responses, suggesting that the noise indeed caused a reweighting effect. Our results indicate that, as for non-speech ABRs, the cochlear place mechanism can represent a potentially substantial confound to speech-ABR-in-noise measurements.

Introduction: Compared to click evoked auditory brainstem response (ABR), speech evoked ABR holds an additional advantage by providing information on neural encoding of speech sounds. There is limited data available on speech ABR, both in normal and pathological ears. Aim: The present study focused on finding the latency‑intensity function of speech evoked ABR in moderate sensorineural hearing loss (SNHL). Materials and Methods: Speech ABR was done using the standardized protocol on 13 ears with moderate SNHL were chosen from 20 participants. Results: Speech ABR recording on these ears produced V Peak till 60 dBnHL which was at the level of 10 dBSL. Results showed that the absolute latency of V Peak at the threshold level, that is, at 60 dBnHL was found to be 8.11 ms; 6.68 ms at 70 dBnHL; 5.96 ms at 80 dBnHL; and 5.41 ms at 90 dBnHL. Conclusion: It can be concluded that using speech as a stimulus in evoked responses, it can result in better estimation of loudness growth pattern in individuals with cochlear pathology. A phenomenon like recruitment can be explored in detail as it gives different results in comparison to click or tone evoked responses.

The temporal relationship between speech auditory brainstem responses and the acoustic pattern of the phoneme /ba/ in normal-hearing adults

Background and ObjectivesCurrently limited information is available on speech stimuli processing at the subcortical level in the recipients of cochlear implant (CI). Speech processing in the brainstem level is measured using speech-auditory brainstem response (S-ABR). The purpose of the present study was to measure the S-ABR components in the sound-field presentation in CI recipients, and compare with normal hearing (NH) children.Subjects and MethodsIn this descriptive-analytical study, participants were divided in two groups: patients with CIs; and NH group. The CI group consisted of 20 prelingual hearing impairment children (mean age=8.90 ± 0.79 years), with ipsilateral CIs (right side). The control group consisted of 20 healthy NH children, with comparable age and sex distribution. The S-ABR was evoked by the 40-ms synthesized /da/ syllable stimulus that was indicated in the sound-field presentation.ResultsSound-field S-ABR measured in the CI recipients indicated statistically significant delayed latencies, than in the NH group. In addition, these results demonstrated that the frequency following response peak amplitude was significantly higher in CI recipients, than in the NH counterparts (p<0.05). Finally, the neural phase locking were significantly lower in CI recipients (p<0.05). ConclusionsThe findings of sound-field S-ABR demonstrated that CI recipients have neural encoding deficits in temporal and spectral domains at the brainstem level; therefore, the sound-field S-ABR can be considered an efficient clinical procedure to assess the speech process in CI recipients.

Evaluation of patients who are unable to provide behavioral responses on standard clinical measures is challenging due to the lack of standard objective (non-behavioral) clinical audiological measures that assess the outcome of an intervention (e.g., hearing aids). Brainstem responses to short consonant-vowel stimuli (speech-auditory brainstem responses [speech-ABRs]) have been proposed as a measure of subcortical encoding of speech, speech detection, and speech-in-noise performance in individuals with normal hearing. Here, we investigated the potential application of speech-ABRs as an objective clinical outcome measure of speech detection, speech-in-noise detection and recognition, and self-reported speech understanding in 98 adults with sensorineural hearing loss. We compared aided and unaided speech-ABRs, and speech-ABRs in quiet and in noise. In addition, we evaluated whether speech-ABR F0 encoding (obtained from the complex cross-correlation with the 40 ms [da] fundamental waveform) predicted aided behavioral speech recognition in noise or aided self-reported speech understanding. Results showed that (a) aided speech-ABRs had earlier peak latencies, larger peak amplitudes, and larger F0 encoding amplitudes compared to unaided speech-ABRs; (b) the addition of background noise resulted in later F0 encoding latencies but did not have an effect on peak latencies and amplitudes or on F0 encoding amplitudes; and (c) speech-ABRs were not a significant predictor of any of the behavioral or self-report measures. These results show that speech-ABR F0 encoding is not a good predictor of speech-in-noise recognition or self-reported speech understanding with hearing aids. However, our results suggest that speech-ABRs may have potential for clinical application as an objective measure of speech detection with hearing aids.

The aims of this study were to systematically explore the effects of stimulus duration, background (quiet versus noise), and three consonant-vowels on speech-auditory brainstem responses (ABRs). Additionally, the minimum number of epochs required to record speech-ABRs with clearly identifiable waveform components was assessed. The purpose was to evaluate whether shorter duration stimuli could be reliably used to record speech-ABRs both in quiet and in background noise to the three consonant-vowels, as opposed to longer duration stimuli that are commonly used in the literature. Shorter duration stimuli and a smaller number of epochs would require shorter test sessions and thus encourage the transition of the speech-ABR from research to clinical practice. Speech-ABRs in response to 40 msec [da], 50 msec [ba] [da] [ga], and 170 msec [ba] [da] [ga] stimuli were collected from 12 normal-hearing adults with confirmed normal click-ABRs. Monaural (right-ear) speech-ABRs were recorded to all stimuli in quiet and to 40 msec [da], 50 msec [ba] [da] [ga], and 170 msec [da] in a background of two-talker babble at +10 dB signal to noise ratio using a 2-channel electrode montage (Cz-Active, A1 and A2-reference, Fz-ground). Twelve thousand epochs (6000 per polarity) were collected for each stimulus and background from all participants. Latencies and amplitudes of speech-ABR peaks (V, A, D, E, F, O) were compared across backgrounds (quiet and noise) for all stimulus durations, across stimulus durations (50 and 170 msec) and across consonant-vowels ([ba], [da], and [ga]). Additionally, degree of phase locking to the stimulus fundamental frequency (in quiet versus noise) was evaluated for the frequency following response in speech-ABRs to the 170 msec [da]. Finally, the number of epochs required for a robust response was evaluated using Fsp statistic and bootstrap analysis at different epoch iterations. Background effect: the addition of background noise resulted in speech-ABRs with longer peak latencies and smaller peak amplitudes compared with speech-ABRs in quiet, irrespective of stimulus duration. However, there was no effect of background noise on the degree of phase locking of the frequency following response to the stimulus fundamental frequency in speech-ABRs to the 170 msec [da]. Duration effect: speech-ABR peak latencies and amplitudes did not differ in response to the 50 and 170 msec stimuli. Consonant-vowel effect: different consonant-vowels did not have an effect on speech-ABR peak latencies regardless of stimulus duration. Number of epochs: a larger number of epochs was required to record speech-ABRs in noise compared with in quiet, and a smaller number of epochs was required to record speech-ABRs to the 40 msec [da] compared with the 170 msec [da]. This is the first study that systematically investigated the clinical feasibility of speech-ABRs in terms of stimulus duration, background noise, and number of epochs. Speech-ABRs can be reliably recorded to the 40 msec [da] without compromising response quality even when presented in background noise. Because fewer epochs were needed for the 40 msec [da], this would be the optimal stimulus for clinical use. Finally, given that there was no effect of consonant-vowel on speech-ABR peak latencies, there is no evidence that speech-ABRs are suitable for assessing auditory discrimination of the stimuli used.

Speech Auditory Brainstem Response through hearing aid stimulation

Correlations between word intelligibility under reverberation and speech auditory brainstem responses in elderly listeners