Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Loudness Perception”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 721 records · Page 40Linked to original sources

Magnitude estimation and cross-modal matching of lingual vibrotactile and auditory sensation.

The present experiment was a preliminary attempt to use the psychophysical scaling methods of magnitude estimation and cross-modal matching to investigate suprathreshold judgments of lingual vibrotactile and auditory sensation magnitudes for 20 normal young adult subjects. A 250-Hz lingual vibrotactile stimulus and a 1000-Hz binaural auditory stimulus were employed. To obtain judgments for nonoral vibrotactile sensory magnitudes, the thenar eminence of the hand was also employed as a test site for 5 additional subjects. Eight stimulus intensities were presented during all experimental tasks. The results showed that the slopes of the log-log vibrotactile magnitude estimation functions decreased at higher stimulus intensity levels for both test sites. Auditory magnitude estimation functions were relatively constant throughout the stimulus range. Cross-modal matching functions for the two stimuli generally agreed with functions predicted from the magnitude estimation data, except when subjects adjusted vibration on the tongue to match auditory stimulus intensities. The results suggested that the methods of magnitude estimation and cross-modal matching may be useful for studying sensory processing in the speech production system. However, systematic investigation of response biases associated with vibrotactile-auditory psychophysical scaling tasks appears to be a prerequisite.

Adolescent↗

Temporal-gap detection by cochlear prosthesis users.

Minimum-detectable gaps for sinusoidal stimuli were measured for three users of a multi electrode cochlear prosthesis as functions of stimulus level, frequency, and electrode place within the cochlea. Stimulus level was scaled by sensation level and by growth-of-loudness functions generated for each condition by direct magnitude estimation. Minimum-detectable gaps decreased with increase in either sensation level or loudness, up to a plateau. When compared at equal sensation levels, the minimum-detectable gaps decreased with frequency increases. The frequency effect on minimum-detectable gaps is reduced if the data are considered at equal loudness. Comparison across place of stimulation within the cochlea showed minimum-detectable gaps to be shorter for more basal electrode placement at low stimulus levels. No differences in minimum-detectable gap as a function of place were found at higher stimulus levels.

Adult↗

Complex and pure-tone signals in the evaluation of hearing-aid characteristics.

In recent years, a number of commercially available systems have been developed to analyze the electroacoustic characteristics of hearing aids. In addition to pure-tone signals, these systems often use a wide variety of complex signals such as broadband noise, clicks, and multitonal complexes. In this paper, a number of practical and theoretical issues concerning the use of pure-tone and complex signals in the evaluation of hearing-aid characteristics are described. The circumstances under which discrepancies in estimated gain and maximum output might occur using these two types of signals are described and the clinical implications of these differences are discussed.

Algorithms↗

Preferred insertion gain of hearing aids in listening and reading-aloud situations.

Nine hearing-impaired subjects with primarily high-frequency hearing loss (Group A) and 8 hearing-impaired subjects with hearing loss in both the high- and low-frequency regions (Group B) participated in the experiment. Subjects wore binaural programmable multimemory hearing aids and selected the preferred amount of insertion gain while they listened to discourse passages read by a male speaker (listen). Subjects also selected the preferred amount of gain while they listened to themselves as they were reading the same passages (read-aloud). Subjects' word-recognition performances and their subjective impressions of the hearing aids determined in listen and read-aloud conditions were examined on subsequent listening and reading tasks. Hearing-impaired subjects preferred more insertion gain in the listen condition than in the read-aloud condition. Different insertion gains led to different objective and subjective performances. Hearing-aid responses selected for a particular condition (listening vs. reading aloud) yielded the best performance in that condition. Assuming the primary purpose of a hearing aid is for amplifying the speech of others, these findings suggest that one should not adjust the gain of a hearing aid using one's own voice as the reference. In addition, one should be careful in soliciting subjective comments from hearing-impaired patients during hearing-aid fittings to avoid underamplifying those individuals in the low frequencies. Multimemory hearing aids may be necessary for some hearing-impaired patients to use their hearing aids satisfactorily in listening and speaking conditions.

Hearing Aids↗

Magnitude estimation and cross-modal matching of auditory and lingual vibrotactile sensation by normal speakers and stutterers.

The present experiment was a preliminary attempt to employ the psychophysical scaling methods of magnitude estimation and cross-modal matching to investigate suprathreshold auditory and lingual vibrotactile sensation magnitude responses for normal-speaking young adults (N = 20) and young adult stutterers (N = 7). A 1000-Hz binaural auditory stimulus and a 250-Hz lingual vibrotactile stimulus were employed for both procedures. Results indicated that the stutterers tended to use more restricted response ranges than the normal speakers for auditory magnitude scaling, and lower response ranges than the normal speakers for lingual vibrotactile magnitude scaling.

Adolescent↗

Notched-noise measures of frequency selectivity in adults and children using fixed-masker-level and fixed-signal-level presentation.

Three experiments were performed to examine the development of frequency selectivity and to attempt to separate peripheral versus central contributions to frequency selectivity. In Experiment 1, frequency selectivity was examined in 4-year-old children, 6-year-old children, and adults, using a fixed-masker-level, notched-noise masking method. Thresholds were determined in a no-notch condition and in conditions in which the notchwidth was 0.3 times the center frequency (0.3 x fc) or 0.6 x fc. The results for the adults and 6-year-olds were similar, but the notched-noise functions of the 4-year-old listeners were relatively shallow. These results were consistent with an interpretation that frequency selectivity is relatively poor in 4-year-old listeners; however, the results of the 4-year-old listeners might also be accounted for in terms of poor processing efficiency. For example, the children may require a relatively high level of signal-related excitation in order for detection to occur. If the growth of excitation is steeper in the no-notch condition than in notched-noise conditions, then thresholds in the notched-noise conditions might be elevated because of poor processing efficiency rather than poor frequency selectivity. This interpretation is consonant with past data showing that the growth of loudness of partially masked signals steepens as a function of increasing masker level: The masker level at the output of the auditory filter centered on the signal frequency would be less for the notched-noise masker than for the masker having no notch. In Experiment 2 the growth of loudness was examined for three adult listeners in the no-notch condition and the 0.6 x fc notched noise. Results showed a steeper growth of loudness in the no-notch case. In Experiment 3, a notched-noise measure of frequency selectivity was used in which the signal level was fixed at 15 dB SL and the masker level was varied adaptively. In this method the noise level at the output of the auditory filter centered on the signal should theoretically be constant over the different notch conditions. Adult and 4-year-old listeners were tested. The notched-noise functions were similar between the adult and 4-year-old listeners. This result supports an interpretation that the shallow notched-noise, fixed-masker-level functions of 4-year-old children may be due to poor processing efficiency rather than to poor peripheral frequency selectivity.

Adult↗

Consistent within-session measures of tinnitus.

Two psychophysical methods, a method of adjustment (MOA) and a forced-choice double-staircase adaptive procedure (FCDS) (Jesteadt, 1980), were used to measure the predominant pitch and loudness of tinnitus for 11 subjects during one test session. The FCDS within-session variability of matches to tinnitus pitch was smaller than for the MOA and comparable to the within-session variability obtained when the FCDS procedure was used to match objective stimuli that approximated the frequency and level of the tinnitus. The within-session variability of matches to tinnitus loudness was nearly identical for the FCDS and the MOA and comparable to the within-session variability obtained when the FCDS procedure was used to match objective stimuli that approximated the frequency and level of the tinnitus. For 3 subjects who participated in 20 sessions, the two psychophysical methods produced correlated measures of tinnitus that tracked each other between sessions. This suggests that tinnitus may be stable within a brief time span but fluctuant in the long run.

Adult↗

Hearing loss, speech, and hearing aids.

Modern hearing aids permit adjustment of a number of electroacoustic parameters, among them frequency response, saturation sound pressure level, and various aspects of compression. Relatively little is known, however, about how the electroacoustic characteristics of hearing aids affect the information-bearing properties of speech. Even less is known about how hearing aids might alleviate or exacerbate the effects of impaired hearing. This article reviews current knowledge in three areas: (a) characteristics of mild/moderate hearing loss, (b) information-bearing aspects of speech, and (c) the relation between electroacoustic characteristics of hearing aids and the speech signal. Concluding suggestions are made regarding the implications of the current data for selecting hearing-aid characteristics.

Acoustic Stimulation↗

Importance of patient and processor variables in determining outcomes with cochlear implants.

Within-subjects comparisons of processing strategies for cochlear implants are reviewed. Compressed analog strategies were compared to interleaved pulses strategies in tests with one group of 8 subjects, and to continuous interleaved sampling strategies in tests with another group of 11 subjects. The tests included open-set recognition of words and sentences. The results show that, while different strategies may produce quite different outcomes across subjects, individual performances with one processing strategy are significantly correlated with those of alternative strategies. These findings emphasize the importance of patient variables in determining outcomes across a variety of prosthesis designs.

Acoustic Stimulation↗

Evaluation of a wide range of amplitude-frequency responses for the hearing impaired.

The long-term average frequency spectrum of speech was modified to 25 target frequency spectra in order to determine the effect of each of these spectra on speech intelligibility in noise and on sound quality. Speech intelligibility was evaluated using the test as developed by Plomp and Mimpen (1979), whereas sound quality was examined through judgments of loudness, sharpness, clearness, and pleasantness of speech fragments. Subjects had different degrees of sensorineural hearing loss and sloping audiograms, but not all of them were hearing aid users. The 25 frequency spectra were defined such that the entire dynamic range of each listener, from 5 dB above threshold to 5 dB below UCL, was covered. Frequency shaping of the speech was carried out on-line by means of Finite Impulse Response (FIR) filters. The tests on speech reception in noise indicated that the Speech-Reception Thresholds (SRTs) did not differ significantly for the majority of spectra. Spectra with high levels, especially at low frequencies (probably causing significant upward spread of masking), and also those with steep negative slopes resulted in significantly higher SRTs. Sound quality judgments led to conclusions virtually identical to those from the SRT data: frequency spectra with an unacceptably low sound quality were in most of the cases significantly worse on the SRT test as well. Because the SRT did not vary significantly among the majority of frequency spectra, it was concluded that a wide range of spectra between the threshold and UCL levels of listeners with hearing losses is suitable for the presentation of speech energy. This is very useful in everyday listening, where the frequency spectrum of speech may vary considerably.

Adult↗

Gap detection as a function of stimulus loudness for listeners with and without hearing loss.

Temporal resolution, or the ability to process rapidly changing stimuli, has been purported to be reduced in some listeners with hearing loss while being described as normal in others. Ensuring stimulus audibility by increasing stimulus levels results in near-normal temporal resolution abilities for many listeners with hearing loss, but may also result in uncomfortably loud stimulus levels. The current study was conducted to describe temporal resolution abilities of listeners with and without hearing loss as a function of stimulus loudness. The gap detection abilities of 8 listeners with normal hearing were compared with those of 8 listeners with mild to moderate hearing losses over a wide range of intensities using a 650-Hz wide high-frequency noise marker. At low intensities, listeners with hearing loss show poor gap detection ability. As intensity increases, most listeners' performance improves and stabilizes near normal at high loudness and sensation levels. At comfortable loudness, gap detection abilities of listeners with hearing loss are less than at loud levels and are considerably poorer than normal.

Adolescent↗

Comparison of two methods for selecting minimum stimulation levels used in programming the Nucleus 22 cochlear implant.

Minimum stimulation levels for active electrodes in a Nucleus 22 cochlear implant were set at threshold (clinical default value) and raised levels (M = +2.04 dB) to determine if raised levels would improve recipients' understanding of soft speech sounds with the SPEAK speech coding strategy. Eight postlinguistically deaf adults participated in a 4-phase A1B1A2B2 test design. Speech recognition was evaluated with consonant-vowel nucleus-consonant (CNC) words in quiet and sentences in noise, both presented at 50, 60, and 70 dB SPL during 2 weekly sessions at the end of each phase. Group mean scores were significantly higher with the raised level program for words and phonemes at 50 and 60 dB SPL and for sentences at 50 and 70 dB SPL. All participants chose to use the raised level program in everyday life at the end of the study. The results suggest that clinical use of a raised level program for Nucleus 22 recipients has the potential to make soft sounds louder and, therefore, more salient in everyday life. Further research is needed to determine if this approach is appropriate for other cochlear implant devices.

Acoustic Stimulation↗

[Use of the round window micro cath for inner ear therapy - results of a placebo-controlled, prospective study on chronic tinnitus].

BACKGROUND: The local therapy of inner ear diseases provides a means of directly applying pharmacological substances and delivering electrical stimulation to inner ear structures. Problems relating to dosage, systemic effects and the blood-cochlear barrier are thus avoided, which is not the case with systemic therapy. The preferred access point is the membrane of the round window. PATIENTS AND METHODS: An appropriately shaped catheter (DURECT Corporation, Cupertino, CA, USA), whose double-lumen passage system permits the variation of concentration and flow, is inserted into the round window niche. In a prospective, placebo-controlled clinical study, this application system was tested in 20 patients with chronic tinnitus. Following implantation the substances lidocaine, glutamate, glutamic acid and caroverine were applied via an attached external micropump. RESULTS: The values for tinnitus loudness, level of irritation caused by the tinnitus and subjective effectiveness of the therapy - measured by means of the visual analog scale (VAS) - showed no significant change, although the most marked improvement was indicated for caroverine. CONCLUSIONS: These results indicate that a positive effect was observable only in a proportion of the patients. Continuous therapy of tinnitus and inner ear diseases will only be possible once a totally implantable microdosage system has been developed.

Administration, Topical↗

[Examination to possibilities of a physiological fitting of cochlear implants].

BACKGROUND: Cochlear implants (CI) convert acoustic events into electrical pulses. The auditory nerve picks these tiny electrical pulses up and sends them to the brain. The dynamics of the audible sound is compressed considerably. The limits for stimulation are determined with the patient. A map law determines which sound pressure level is assigned to which stimulation level. A sufficient speech understanding requests an allocation of high stimulation levels for weak sound signals. The higher the sound level, the lower the increase. Unfortunately, with such kind of map law unwanted background noise is also presented as well audible stimulation. These stimuli are often annoying to CI users in everyday situations. PATIENTS AND METHOD: The possibility to give an s-shaped course to these map laws was examined in 9 patients. After the fitting procedure their speech understanding were tested. The results were compared with the results of former tests. RESULTS: 8 patients reported definite improvement of their hearing situation. Such map laws seem, therefore, suitable to optimise speech processor programming.

Adult↗

The science and practice of LSVT/LOUD: neural plasticity-principled approach to treating individuals with Parkinson disease and other neurological disorders.

Our 15 years of research have generated the first short- and long-term efficacy data for speech treatment (Lee Silverman Voice Treatment; LSVT/LOUD) in Parkinson's disease. We have learned that training the single motor control parameter amplitude (vocal loudness) and recalibration of self-perception of vocal loudness are fundamental elements underlying treatment success. This training requires intensive, high-effort exercise combined with a single, functionally relevant target (loudness) taught across simple to complex speech tasks. We have documented that training vocal loudness results in distributed effects of improved articulation, facial expression, and swallowing. Furthermore, positive effects of LSVT/LOUD have been documented in disorders other than Parkinson's disease (stroke, cerebral palsy). The purpose of this article is to elucidate the potential of a single target in treatment to encourage cross-system improvements across seemingly diverse motor systems and to discuss key elements in mode of delivery of treatment that are consistent with principles of neural plasticity.

Deglutition Disorders↗

[Improvement of hearing aid fitting with digital aids and new fitting strategies].

Hearing aids with digital signal processing demonstrate a large dynamic range with negligible distortion and no significant inherent noise. Furthermore, many acoustic parameters allow the compensation of even severe hearing loss, and the adjustment is extremely accurate. However, the new hearing aid generation not only requires computerized fitting, but also an experienced examination with new integrated fitting procedures. In addition to in situ measurement, the hearing aid fitting should include not only the Freiburg speech test, but also the Göttingen sentence test and the monosyllable rhyme test with different noises, for example the Fastl noise or the Döring babble noise. Loudness scaling with different methods is particularly important.

Analog-Digital Conversion↗