Speech Discrimination Testing
If a patient is struggling with clarity of speech and the hearing aid does not seem to be helping we can check a patients discrimination by a speech test. Instead of responding to pure tones we introduce words which we ask them to repeat. From this, we can tell if the aid needs to be programmed differently or if the patient does have bad discrimination naturally, due to nerve damage.
We also see patients referred to us for speech testing from ENT if they are a candidate for a stapedectomy, as the doctor can check how well the patient may respond to speech after the operation.
Patients are offered to be referred on to hearing therapy by ENT or audiologists. It provides a rehabilitative service for adults who have hearing difficulties and /or associated disorders. It gives support, advise and information to patients who need help in managing their hearing difficulties.
Tinnitus retraining Therapy (TRT)
If you wish to refer a patient for TRT, they need, at present, to be referred to ENT first, in case further investigations are needed. ENT can then refer onto us. The initial appointment is an hour long, a full history is taken, the ears are checked, advise given and a treatment plan made for further appointments.
Auditory Brainstem Response
ABRs can be used in 2 different ways, testing a patients threshold of hearing, or testing the neurological pathways.
ABR threshold testing is not normally undertaken on adults, but if a person is not consistent on audiometry or non organic we can test them with ABR so we are not relying on subjective responses.
ENT will generally request a neurological ABR if for example a acoustic neuroma is suspected but the patient cannot have a MRI.
Requested by ENT to investigate vertigo. It tests inner ear and central motor functions. We use it to determine if a vestibular problem may be causing imbalance or dizziness.
VNG is a diagnostic system which records nystagmus. A pair of goggles are worn while the patient looks or lies in different positions. We obtain responses in the light as well as in the dark to see if the reactions differ. This can indicate whether there is a central or peripheral problem.
Video Head Impulse test (VHIT)
The video head impulse test is an ear-specific test that detects disorders of the vestibular-ocular reflex and identifies which ear is affected; in cases of peripheral vestibular loss. It is adapted from Drs. Halmagyi and Curthoys bedside test. The patient wears goggles which include a small high-speed camera that focuses on the patient’s pupil. The goggles link up with a PC. When the clinician turns or “impulses” the patients head at a high velocity left or right the camera goggles let the clinician know if the pupil has moved in the opposite direction, at the same speed as the head impulse.
Patients with a vestibular loss will exhibit a corrective saccadic eye movement and the gain of the head in comparison to the eye will not be equal. The head impulse test provides information about the vestibular-ocular reflex to stimuli in the high-frequency range.
Vestibular Evoked Myogenic Potentials (VEMP)
Acoustic stimulation of the saccule gives rise to an ipsilateral reflex which can be measured at the sternocleidomastoid (SCM) muscle in the neck, using electrodes. The patient has electrodes attached to their head and neck and is asked to tense their SCM by turning their head left or right at the same time loud clicks are delivered into the patient’s ear via a headphone. The electrical activity of the SCM muscle is measured by the electrodes. The purpose of the VEMP test is to determine if the saccule, as well the inferior vestibular nerve are working normally. The test is particularly useful to help diagnose superior canal dehiscence.
A VNG is usually tested in conjunction with a caloric which measures responses to warm and cold water being introduced to each ear. This will provide us with information to determine if one vestibular system is working more than the other and causing vertigo.