Table 2 Summary of eighteen articles on the effect of tinnitus on CAP

Rossiter and Walker [13]

To investigate the relationship between tinnitus and cognition

Clinical group: 19 adult patients with tinnitus, with 34 to 3 years old (mean = 48.9 years, SD = 8.2)

Control group: 19 normal hearing adults without tinnitus, with 34 to 63 years old (mean = 48.8 years, SD = 8.8)

Reading span test

Reading span affected in tinnitus group

Huang et al. [7]

To investigate the following:

• The effect of tinnitus on speech perception

Clinical group: 20 adults (13 M and 7 F) with tinnitus, mean age — 40.75 years old (range 22–62 years)

Control group: 20 healthy adults (12 M and 8 F) without tinnitus, mean age — 38.35 years old (range — 29–56 years)

MSPIN, tinnitus loudness scale, THI

• MSPIN-tinnitus group had less scores in high and low predictability list scores

Sanches et al. [4]

• To compare the results of the GIN test in normal listeners with and without tinnitus

Clinical group: 18 tinnitus patients with normal hearing (3 M, 15 F) aged between 21 and 45 years, mean age — 31.3 years

Control group: 23 normal hearing participants (8 M, 15 F) aged between 21 and 45 years, mean age — 29.7 years

GIN test

GIN is affected in tinnitus group

Gabriela, Sanches, and Ganz [21]

To analyze auditory temporal resolution in tinnitus patients using GIN

Clinical group: 20 adults with tinnitus, mean age: 33.5 years

Control group: 28 participants with no tinnitus

Mean age: 28.8 years

GIN

GIN is affected in tinnitus group

An et al. [22]

Effect of tinnitus on localization

Clinical group: 40 adults (15 M and 25 F) with tinnitus

Mean age — 36.7 years (range — 14–63 years)

Control group: 40 adults (14 males and 26 females)

Mean age — 39.3 years (range = 16–62 years)

SLT at 30-degree resolution for a total of 180° on the horizontal plane in front of the listener

Distance 1 m

• Mean TES significantly greater in the tinnitus group than in the control group

Ryu et al. [14]

To evaluate the effects of masking noise on speech perception ability in patients with normal hearing but unilateral chronic tinnitus

Clinical group: 20 adult patients with unilateral tinnitus, with 20 to 35 years old tinnitus

Control group: 20 normally hearing adults without tinnitus, with 20 to 35 years old

K-HINT

RTS (quiet)

SNR

Tinnitus group had reduced values than the control group

Gilani et al. [5]

To assess temporal processing in individuals with tinnitus

Clinical group: 20 individuals with tinnitus

Mean age: 30.31 ± 9.35 years

Control group: 20 individuals without tinnitus, mean age: 27.80 ± 7.74 years

GIN, DPT

GIN is affected in tinnitus group

Fournier and Hébert [20]

To investigate the gap paradigm in high-frequency tinnitus

Clinical group: 15 adult patients, 19 to 61 years old (mean age = 28.5 years, SD = 6), with tinnitus

Control group: 17 normally hearing adults without tinnitus; mean age = 23 years (SD = 3)

Gap startle paradigm

Impaired perception of gap in tinnitus group

Jain and Sahoo [8]

To investigate the effect of tinnitus on the temporal perception, frequency, and intensity discrimination and speech perception ability in noise in persons with normal hearing sensitivity

Clinical group: 20 normal hearing individuals with tinnitus

Age range: 18–55 years (mean age: 38.1 years)

The clinical group was further subdivided into mild tinnitus group (10 subjects; 6 M, 4 F) and moderate tinnitus group (10 subjects; 6 M,4 F)

Control group: 20 normal hearing participants without tinnitus

Age range: 18–55 years (mean age: 38.1 years)

GDT, MDT, DLF, DLI, Kannada QuickSIN

GDT, MDT, DLF, and Kannada QuickSIN were affected in tinnitus group, and no difference was seen in DLI

Shakarami et al. [29]

To compare the verbal auditory memory between individuals with normal hearing with and without tinnitus

Clinical group: 16 adults (6 males and 10 females) with tinnitus

Mean age — 36.44 years (range — 23–53 years)

Control group: 20 adults (3 males and 17 females) without tinnitus

Mean age — 33.65 years (range — 21–49 years)

DAVMT, RDDT

• No significant differences seen

Moon et al. [10]

To investigate the pathophysiology of tinnitus using psychoacoustic assessments of auditory spectral and temporal resolution and speech perception in noise

Clinical group: 9 unilateral tinnitus subjects with normal hearing thresholds (group 1 mean age — 28.22 +  − 9.22 years), 12 unilateral tinnitus subjects with hearing loss (group 2 mean age — 56.08 +  − 12.92 years), 9 bilateral tinnitus subjects with symmetrical hearing loss (group 3 mean age — 60.67 +  − 10.98 years)

Control group: 15 normally hearing adults without tinnitus, with less than 30 years old (mean age − 44.93 +  − 9 years)

SRD, TMD SPD, and SRT

• No significant differences in SRD, TMD, and SPD

• The TEs showed poorer SRTs than the NTEs

Gilles et al. [6]

To assess differences in audiological characteristics between noise-exposed adolescents with and without NIT

Clinical group: 19 adult patients with unilateral tinnitus, participants age was less than 30 years old

Control group: 68 normally hearing adults without tinnitus, with less than 30 years old

Speech-in-noise testing list

Scores were affected in tinnitus group

Jain and Dwarkanath [9]

To assess psychoacoustic abilities in individuals with tinnitus

Control group: 38 participants (19 M & 19 F)

Mean age — 33.7 years

UTG — 22 participants (9 M and 13 F)

Mean age — 34.7 years

BTG — 16 participants (8 M and 8 F)

Mean age — 38.3 years

All participants were in the age range of 24–50 years

GIN, TMTF, DDT, backward masking, DPT

DPT — no difference was observed

GIN, TMTF, DDT, and backward masking affected in tinnitus

Tai & Husain [15]

To investigate how tinnitus interferes with speech recognition ability in noise, and to examine the impact of tinnitus (severity or loudness) on speech recognition

Clinical group: 14 adults with chronic bilateral tinnitus, mean age — 43.86 years

Control group: 14 adults with no history of tinnitus, mean age — 44 years

QuickSIN

Tinnitus group required more SNR than the control group

• At 10–25-dB SNR conditions, there was no significant between-group difference

• No significant correlation

Ravirose, Thanikaiarasu, and Prabhu [12]

To determine the DDT, DLI, and DLF thresholds in patients with tinnitus

Fifteen participants with tinnitus in the age range of 18 to 40 years (mean age = 29.47 and SD = 7.20) with their hearing thresholds at normal limits

DDT, DLI, and DLF

DDT, DLI, and DLF are affected in tinnitus

Kondli, Amruthavarshini, and Prashanth [30]

• To evaluate the performance of auditory working memory tasks in adults with tinnitus

Clinical group: 15 individuals with tinnitus

Mean age: 32.7 years (SD = 6.25)

Control group: 15 individuals without tinnitus

Mean age: 33.4 years (SD = 9.7)

Digit forward span, backward span, ascending span, and descending span tasks

• Poor backward span, ascending span, and descending span tasks but not the forward digit span

Mohanapriya [31]

To evaluate the amplitude modulation discrimination function in terms of depth and rate discrimination in individuals with normal hearing sensitivity having tinnitus

Clinical group: 20 individuals with normal hearing sensitivity with tinnitus

Age rage — 18–45 years

Control group: 20 individuals with normal hearing sensitivity without tinnitus

PTA, immittance audiometry, tinnitus evaluation, AMDD, AMRD

Depth discrimination was comparable, but the rate discrimination was affected in tinnitus group

Raj et al. [11]

To compare the auditory processing abilities of two groups: those with normal hearing and tinnitus and a similar group who did not have tinnitus

Clinical group: 54 adult patients, 19 to 61 years old (mean age 37.1 years, SD = 10.7)

Tinnitus for 3.8 (SD = 2.5) years

Control group: 43 normally hearing adults without tinnitus. The mean age was 35.5 years (SD = 11.1)

FPT, DPT, GDT, and DLT

GDT and DLT were affected in tinnitus group, and no difference was seen in FPT and DPT. And right ear advantage was absent