Vocal load plays a significant role in the aetiology of voice disorders and influences the response to treatment. For this reason, many researchers have focused their attention on how a voice is ...used, especially when vocal load is increased, during working hours for instance. The majority of studies in this regard have been performed by recording vocal parameters for brief periods with the aid of microphones. The first devices produced recorded only a few parameters and for relatively short periods of time, and since microphones were used there was a problem with both privacy and background noise such as the inclusion of voices from nearby people. Recently, microprocessors that can monitor a voice for an entire day have been developed; these use miniaturised accelerometers as vocal sensors. The latest commerciallyavailable version is the Ambulatory Phonation Monitor (APM) (KayPENTAX, Lincoln Park, NJ, USA) which can record several vocal parameters for over 18 hours and supply a series of graphic representations of the variations in these parameters during the recording period. In particular, the APM permits recording vocal load by measuring the cycle dose and distance dose, and evaluates vocal intensity (dB sound pressure level SPL), fundamental frequency and total phonation time. This report describes the APM, the use of an accelerometer as a vocal sensor, the importance of its calibration and the parameters it records. In particular, details are given on phonation time, variations in frequency, vocal intensity, phonation density and vocal dose. The role of the APM in voice studies is also described, in addition to its potential clinical applications as demonstrated by the few reports available in the literature. We also discuss our experience with the device in groups of euphonic and dysphonic elementary school teachers.
Vocal nodules are organic lesions, common in adults & children. The etiopathogenesis is influenced by many factors even if voice abuse plays an important role. In adult, voice abuse is correlated to ...excessive muscle tension, especially when speaking loudly or excessively. The pathogenic mechanism is mainly connected to alterations in pneumo-phono-articulate coordination; generally there is temporary hypotonicity of the vocal cords, a counteraction of the hyperkinetic type follows, in the attempt to maintain adequate vocal emission. To reach a correct diagnosis, the main examination is the laryngostroboscopy, with which it is possible to identify the nodules & the tension adductor defect in the vocal fold. The electroacoustic examinations of the voice are very useful in evaluating the dysphonia & reaching a positive result, obtained through adequate treatment in speech therapy/rehabilitation. In our study we examined 45 patients suffering with dysfunctional dysphonia associated with bilateral nodules evaluated through an electroacoustic analysis of the voice (spectrogram & MDVP), performed before & after rehabilitation treatment. The spectrographic evaluation of the vocal signal showed results globally significant, more so when the dyphonia was initially severe. Even the data that emerged from the MDVP evaluation showed a global improvement after the rehabilitation therapy. The indexes that evaluate the perturbation of frequency & amplitude (jitt, vFo, Shim & vAm) all showed improved capability to maintain a periodical vibration; an improved NHR, indicating a global reduction in the sound & an improvement in SPI, expressing a major adductor force on the cords during the phonetic act; ATRI & FTRI, instead, showed a reduction in the tremor. To confirm these results, we considered each single patient that came within the normal range of the MDVP parameters after therapy; we can say that in 60% of the cases, there was an improvement. Improvements in the vocal performance are certainly connected to the effect of the speech therapy/rehabilitation on the function of the pneumo-phono-articulation system. In fact the treatment, centered above all on the imposition of the voice, has also concentrated its attention on the knowledge & learning of other actions which need be corrected such as: breathing, posture, resonance & vocal projection. The results of our study have also shown that not only does the rehabilitation therapy represent a gold standard in cases of vocal nodules, but like the electroacoustic examinations of the voice, these are above all, very useful in obtaining positive vocal results through speech therapy. Adapted from the source document
