Effect of hypoglossal nerve stimulation on snoring: an evaluation using objective acoustic parameters.

STUDY OBJECTIVES: Hypoglossal nerve stimulation is an established therapy for sleep apnea syndrome. Whether or not this therapy on snoring and nighttime noise exposure is effective and how strong this effect may be has not been objectively investigated thus far and was the aim of this study. METHODS: In 15 participants (14 males; age: 30-72 years; mean: 51.7 years), polysomnography and acoustic measurements were performed before and after hypoglossal nerve stimulation. RESULTS: The therapy led to a significant improvement in sleep apnea (apnea-hypopnea index from 35.8 events/h to 11.2 events/h, P < .001). Acoustic parameters showed a highly significant reduction in the average sound pressure level (42.9 db[A] to 36.4 db[A], P < .001), averaged sound energy, A-weighted (LAeq; 33.1 db[A] to 28.7 db[A], P < .001), snoring index (1,068 to 506, P < .001), percentage snoring time (29.7-14.1%, P < .001), and psychoacoustic snore score, the latter being a measure of annoyance due to snoring (47.9 to 24.5, P < .001). CONCLUSIONS: This study was able to show for the first time by means of objective acoustic and psychoacoustic parameters that hypoglossal nerve stimulation can not only cause a significant improvement in sleep apnea but also has a positive effect on snoring and thus noise annoyance experienced by the bed partner. CLINICAL TRIAL REGISTRATION: Registry: German Clinical Trials Register; Name: Effect of Hypoglossal Nerve Stimulation on Snoring: An Evaluation Using Objective Acoustic Parameters; URL: https://drks.de/search/de/trial/DRKS00032354; Identifier: DRKS00032354. CITATION: Fischer R, Vielsmeier V, Kuehnel TS, et al. Effect of hypoglossal nerve stimulation on snoring: an evaluation using objective acoustic parameters. J Clin Sleep Med. 2024;20(3):363-370.

Are annoyance scores based on sound pressure levels suitable for snoring assessment in the home environment?

PURPOSE: An objective statement about the annoyance of snoring can be made with the Psychoacoustic Snore Score (PSS). The PSS was developed based on subjective assessments and is strongly influenced by observed sound pressure levels. Robustness against day-to-day interfering noises is a fundamental requirement for use at home. This study investigated whether or not the PSS is suitable for use in the home environment. METHODS: Thirty-six interfering noises, which commonly occur at night, were played in the acoustic laboratory in parallel with 5 snoring sounds. The interfering noises were each presented at sound pressure levels ranging from 25 to 55 dB(A), resulting in 3255 distinct recordings. Annoyance was then assessed using the PSS. RESULTS: In the case of minimally annoying snoring sounds, interfering noises with a sound pressure level of 25 dB(A) caused significant PSS changes from 40 to 55 dB(A) for annoying snoring sounds. If the interfering noise was another snoring sound, the PSS was more robust depending on the sound pressure level of the interfering noise up to 10 dB(A). Steady (no-peak) interfering noises influenced the PSS more strongly than peak noises. CONCLUSIONS: The PSS is significantly distorted by quiet interfering noises. Its meaningfulness therefore depends strongly on the acoustic environment. It may therefore be assumed that scores dependent on sound pressure level are suitable for measurements when there is minimal ambient noise, as in the sleep laboratory. However, for measurements where noise is incalculable, as in the home environment, interfering noises may distort the results.

Snoring: is a reliable assessment possible?

PURPOSE: It is not easy to assess how severe and annoying a patient's snoring is. Solid parameters are lacking; snorers cannot deliver a reliable self-assessment and it is uncertain whether bed partners' statements can be relied upon. The purpose of the present study was therefore to investigate whether and how well snoring assessment based on acoustic parameters and bed partners' reporting agree. METHODS: In a double-blind, placebo-controlled study on snoring treatment, several acoustic parameters [snoring index (SI), percentage snoring time (ST), sound pressure level, sound energy, loudness, psychoacoustic annoyance and psychoacoustic snore score (PSS)] were measured in 18 subjects during 24 polysomnographies. Bed partners also assessed snoring annoyance and loudness as well as treatment outcome. RESULTS: No correlation was found between the subjective annoyance caused by snoring and the acoustic parameters. Regarding perceived loudness, there was a moderate, significant correlation with loudness (N5) and PSS over the hour with the highest SI. SI, ST, LAeq and maximum sound pressure level dB(A)max showed no significant correlation. After the intervention only mean sound energy LAeq over the entire night showed a significant correlation (rs = 0.782; p = 0.022) with bed partners' assessments. However, this result was not confirmed in the second control night. CONCLUSIONS: The non-existent or only weak correlation between bed partners' ratings and objective parameters indicate that snoring severity should be evaluated with caution. Neither acoustic parameters, at least for one measurement over just one night, nor bed partners' ratings should be used as the sole basis for snoring assessment.

Calculating annoyance: an option to proof efficacy in ENT treatment of snoring?

To develop and validate an objective method for calculating the annoyance caused by snoring sounds. 53 subjects assessed 50 different snoring and breath sounds on a visual analog scale for level of annoyance. A linear regression analysis was used to correlate these subjective assessments with objectively calculated psychoacoustic parameters (loudness, roughness, sharpness, and fluctuation strength, calculating the maximum, mean, and 5th percentile in each case). The quality of the resulting formula was checked, and additional validation was performed using subjective assessments of 60 new snoring and breath sounds by 52 new subjects. Receiver operating characteristic (ROC) analysis was used to scale the annoyance ranges obtained with the formula. A score consisting of the 5th percentile of loudness and the mean of roughness was developed. The formula displays high goodness of fit (R 2 = 0.91) and quality. In the validation phase, a highly significant correlation (r s = 0.95; p < 0.01) was obtained between the scores calculated with the formula and the subjective assessments. ROC analysis was able to define the annoyance ranges with a discriminatory power between 52 and 73 % (optimum sensitivity/specificity). The subjective assessments made by the participants were distinctly scaled and were reflected in a psychophysical algorithm. In the setting of polygraphy and polysomnography, this means that a reliable annoyance score that is not dependent on the bed partner can be obtained to establish the indication for anti-snoring treatments and to review their utility.

Are subjective assessments of snoring sounds reliable?

The aim of this study is to investigate whether snoring sounds can be reliably, i.e. reproducibly and comparably, assessed by the listener. This is an absolute prerequisite if an objective method is to provide a valid representation of subjective assessments of snoring sounds. Fifty-three subjects, both men and women, from different age categories assessed snoring sequences in terms of their annoyance level. This was done using a paired comparison model with ten sequences, once at original volume and once at adjusted peak level. In addition, assessments of 50 sequences were made using a visual analog scale (VAS). In the first paired comparison the assessments displayed very high consistency (K = 0.94) and high concordance (W = 0.83). The results showed very good agreement between the sexes (r s = 0.98), between different levels of snoring-related experience (r s = 0.99) and between different ages (r s = 0.98). At adjusted peak level there was also very high consistency (K = 0.91) although concordance was clearly lower (W = 0.50). The rankings in the two paired comparisons showed a high degree of correlation (r s = 0.81). The assessments on the VAS revealed good inter-rater reliability (α = 0.73) and a high degree of correlation with the result of the first paired comparison (r s = 0.93). Snoring sounds can be assessed in a reproducible and comparable manner in terms of their annoyance level. There are no gender-specific differences, and age-specific and experience-specific differences also appear to be negligible. While volume plays a dominant role, other characteristics of the sounds are also sufficient to permit an assessment.

Distinguishing snoring sounds from breath sounds: a straightforward matter?

BACKGROUND: Although snoring is a common problem, no unequivocal definition yet exists for this acoustic phenomenon. The primary study objective was to investigate whether snoring sounds can be distinguished at all clearly from breath sounds. Our secondary objective was to evaluate whether the sound pressure level in common use and psychoacoustic parameters are suitable for making this distinction. METHODS: Twenty-five subjects exposed to 55 sound sequences were asked to decide whether these were breath sounds or snoring sounds, and to indicate how certain they were about their decision. The sound pressure level and the psychoacoustic parameters of loudness, sharpness, roughness, and fluctuation strength were then analyzed, and psychoacoustic annoyance was calculated from these parameters. RESULTS: Sixteen percent of the sound sequences could not be classified unequivocally, although the individual raters stated that they were still moderately certain about their decision. The sound pressure level and psychoacoustic parameters were capable of distinguishing between breath sounds and snoring sounds. The optimum for sensitivity and specificity was 76.9 and 78.8 %, respectively. CONCLUSIONS: Because snoring appears to be a subjective impression, at least in part, a generally valid acoustic definition therefore seems to be impossible. The sound pressure level and psychoacoustic parameters are suitable for distinguishing between breath sounds and snoring sounds. Nevertheless, when interpreting results, the only moderate validity of these parameters due to the absence of a universally valid definition of snoring should be taken into account.

The nasal cycle during wakefulness and sleep and its relation to body position.

OBJECTIVES/HYPOTHESIS: To compare the occurrence, duration, and relative amplitudes of the nasal cycle (NC) during wakefulness and sleep, and to investigate the relationship of the NC to body position. STUDY DESIGN/METHODS: In 20 healthy subjects, the NC was measured by long-term rhinoflowmetry for an average 23.1 hours during wakefulness and sleep. Head and body position were also recorded during the night. RESULTS: A classic NC was displayed by 50% of subjects during wakefulness and by 75% of the subjects during sleep. Cycle duration during wakefulness was 91.1 minutes (± 65.2; 20-337), increasing significantly during sleep to 178 minutes (± 92.8; 21-498) (P < 0.01). The relative mean flow of the working phase during wakefulness was 67.6% (± 8.0; 58-90), and it was significantly higher during sleep at 82.0% (± 6.8; 63-93) (P < 0.01). On recumbency, there was a significant correlation between body position and resting phase side (r = 0.67; P = 0.024). To a significant extent, positional shifts led to subsequent NC laterality changes (22%; P < 0.01). Conversely, to a significant extent, positional shifts preceded NC laterality changes (57.6%; P < 0.01). Body position changed in a nonsignificant number of cases (30.3%; P = 0.16) due to reversal of the congestion side of the inferior turbinates. CONCLUSION: The results of our study show that the NC during sleep is characterized by longer cycle durations and greater amplitudes than during wakefulness on normal physical activity. Shifts in body position during sleep alter the NC in a specific direction to a significant extent, but the opposite is not the case. LEVEL OF EVIDENCE: 4.

The annoyance of snoring and psychoacoustic parameters: a step towards an objective measurement.

The aim of this study was to find out whether objective analysis of snoring sounds (sound pressure level and psychoacoustic parameters) correlates with the subjective rating by participants with respect to perceived annoyance and hence whether it is useful. 43 participants, aged 22-65 years with normal hearing, were asked to rate 60 snoring sounds from simple and obstructive snorers according to their level of annoyance. A correlation analysis according to Spearman was then performed on objectively calculated parameters. These were the A-weighted sound pressure level, the psychoacoustic parameters of loudness, sharpness, fluctuation strength and roughness and psychoacoustic annoyance (PA) calculated from those parameters. The subjective ratings showed high, highly significant correlations with, in particular, the mean A-weighted sound pressure level (r = 0.88; p < 0.01), the 5th percentile of psychoacoustic loudness (r = 0.89; p < 0.01) and psychoacoustic annoyance (r = 0.80; p < 0.01). These parameters seem to provide information about the degree of annoyance that is objectively measurable and independent of the snorer's bed partner. Further studies should follow in order to confirm these results, find out their generalizability and establish reference values.

An intradermal nevus of the external auditory meatus.

We herein describe a rare case of an intradermal nevus arising in the external auditory meatus. A 36-year-old woman presented with progressive hearing loss on the right ear, and otomicroscopic examination revealed the presence of a large, violaceous, dome-shaped, papillomatous lesion originating from the posterior wall of the external canal of the right ear. Upon excisional biopsy, the tumor was diagnosed as an intradermal nevus. Thus, this is a unique case of intradermal nevus obstructing the external ear canal with the patient presenting with progressive hearing loss. The possibility of a benign nevomelanocytic nevus should not be underestimated when evaluating a lesion obstructing the ear canal, and all melanocytic nevi should be excised instead of biopsied to rule out melanoma.

Clonidine premedication in patients with sleep apnea syndrome: a randomized, double-blind, placebo-controlled study.

Patients with sleep apnea often present with cardiac diseases and breathing difficulties, with a high risk of postoperative respiratory depression. We conducted a randomized, double-blind, prospective study in 30 adult patients with obstructive sleep apnea, undergoing elective ear-nose-throat surgery. The patients were randomly assigned to receive placebo or clonidine (2 microg/kg oral) the night before and the next morning 2 h before surgery. Spo2, heart rate, mean arterial blood pressure, snoring, and oronasal airflow were monitored for 36 h. A standard anesthesia was used consisting of propofol and remifentanil. Anesthetic drug consumption, postoperative analgesics, and pain score were recorded. In the clonidine group, mean arterial blood pressures were significantly lower during induction, operation, and emergence from anesthesia. Both propofol dose required for induction (190 +/- 32.2 mg) and anesthesia (6.3 +/- 1.3 mg . kg(-1).h(-1)) during surgery were significantly reduced in the clonidine group compared with the placebo group (induction 218 +/- 32.4, anesthesia 7.70 +/- 1.5; P < 0.05). Piritramide consumption (7.4 +/- 5.1 versus 14.2 +/- 8.5 mg; P < 0.05) and analgesia scores were significantly reduced in the clonidine group. Apnea and desaturation index were not different between the groups, whereas the minimal postoperative oxygen saturation on the day of surgery was significantly lower in the placebo than in the clonidine group (76.7% +/- 8.0% versus 82.4% +/- 5.8%; P < 0.05). We conclude that oral clonidine premedication stabilizes hemodynamic variables during induction, maintenance, and emergence from anesthesia and reduces the amount of intraoperative anesthetics and postoperative opioids without deterioration of ventilation.