You are welcome, you can have it with unilateral as well or if you have one dominant one that is compressed and a hypoplastic IJV which add up to to bilateral stenosis. One good thing that the study reported is that most of the folks who had the hearing loss improved after normalization of CSF pressure (although I wonder by how much, SNHL is usually permanent in most cases but it is promising to know that some recover)
Hearing loss and vestibular dysfunction
Hearing loss of variable degree is a symptom reported by 30%–85% of patients with IIH.[17,108] Earlier studies of patients with presumed pseudotumor cerebri, including those with IIH mimics such as cerebral venous sinus thrombosis, characterized the hearing loss as sensorineural affecting the lower frequencies (250 and 500 Hz).[17] A recent study of IIH patients (2002 modified Dandy criteria[2]) found asymmetry of the frequencies affected in each ear.[108] Lowering CSF pressure into the normal range led to improved hearing, particularly in the lower frequencies.[17,109]
Hearing loss as a prominent presenting feature of IIH has been reported in five patients [Table 6].[110,111,112,113,114] Four patients presented with bilateral sensorineural hearing loss, and one had unilateral conductive hearing loss.[113] The diagnosis of IIH was questionable in four patients, due to the absence of papilledema or insufficient imaging to exclude venous sinus thrombosis.[110,111,113,114] Hearing improved between one day and six months after normalization of CSF pressure in all five patients.
I also talked about it here a while ago with data from a research on the internet. The unilateral appears to be less than 50% ( ~ 40% or less).