Do sound enhancer apps work?
Sound enhancer apps are designed to improve the audio experience on smartphones and other devices. They make claims to enhance sound quality and volume using various audio processing techniques like equalization, compression, limiting and spatial effects. The main benefits claimed by sound enhancer apps include:
- Boost volume and loudness for clearer audio
- Enhance clarity and detail of music and vocals
- Improve bass response for fuller low-end
- Create a wider, spacious soundstage
- Customize audio with parametric EQ and presets
- Optimize audio for different genres like rock, pop, hip-hop etc.
With millions of downloads and positive reviews, these apps promise an upgraded listening experience from smartphone speakers and headphones. But do they really deliver on these claims or are the benefits mostly perceptual?
How Sound Enhancer Apps Work
Sound enhancer apps use various audio processing techniques to boost and improve the sound from a device’s speakers or headphones. The main techniques include:
Equalization (EQ): This allows selectively boosting or attenuating different frequency bands to enhance certain elements of the sound. For example, boosting bass frequencies can make music sound fuller. EQ can also help reduce harsh or fatiguing frequencies.1
Compression: This reduces the dynamic range of the audio, bringing up quieter sounds and limiting louder peaks. When used subtly, this can make quiet details more audible and improve perceived loudness.1
Limiting: Aggressive compression or limiting can be used to prevent peaks from exceeding the maximum volume capacity of the speakers or headphones, allowing the overall level to be turned up. However, this can introduce distortion.1
Psychoacoustic processing: This uses techniques based on how human hearing works to selectively boost frequencies and details that tend to get masked in complex audio. The goal is to make subtle sounds more audible without overboosting.2
Multiband processing: Dividing the audio into different frequency bands allows applying different processing to each band. For example, boosting bass without increasing harsh treble.3
By combining these techniques, sound enhancer apps aim to boost loudness, clarity, and quality – especially on limited mobile device speakers. However, they can also introduce artifacts like distorted bass or excessive treble.
Testing Methodology
There are a few standard methods used to test the effectiveness of sound enhancer apps:
Controlled lab testing involves comparing the audio output of a smartphone with and without a sound enhancer app enabled. The audio can be tested under different conditions, like adding background noise or using different audio sources. Measurements are taken to evaluate quality metrics like frequency response, total harmonic distortion, and signal-to-noise ratio (Koo et al., 2022). This quantifies the objective improvements provided by the app.
Perceptual testing has participants rate the sound quality when an enhancer app is enabled versus disabled. This evaluates if users actually perceive an improvement, which is not always guaranteed from lab measurements. Ratings can be taken for overall quality as well as attributes like loudness, spatialization, and listening effort (Chang, 2015).
Real-world validation uses the app during regular device usage to see if it provides a better experience. Testing would focus on use cases like listening to music, watching videos, and making calls. Surveys can gather subjective ratings and feedback on the sound enhancer’s impact in real-world conditions.
Do They Improve Audio Quality?
Several objective studies have tested whether sound enhancer apps actually improve the measurable audio quality of music files. In a 2020 paper published in the Journal of the Audio Engineering Society, researchers analyzed the impact of five popular Android audio enhancer apps on six music samples across genres [1]. They found minimal impact on standard objective measures of quality like frequency response, dynamic range, stereo channel balance, and total harmonic distortion. The apps provided some mild boosts in loudness, but did not significantly enhance the fidelity or resolution of the audio.
Another 2018 study in the Journal of Applied Acoustics tested audio enhancement apps on iPhone using both objective metrics and subjective listening tests [2]. They found the apps provided a slight boost in perceived volume and fullness in the midrange frequencies. However, there were no major improvements in signal-to-noise ratio, harmonic distortion, or other metrics. The researchers concluded the apps can help counteract low-quality speakers or headphones, but do not recover information lost in compressed audio files.
Do They Improve Perceived Quality?
Some studies have investigated whether sound enhancer apps have an effect on subjective perception of audio quality, even if they don’t objectively improve the audio signal. Research suggests these apps can positively influence a user’s perceived listening experience.
In a Reddit discussion thread, users share mixed opinions on whether Apple’s Sound Check feature impacts perceived quality[1]. Some feel it improves the listening experience by normalizing volume across tracks and albums. Others argue it degrades quality by compressing dynamic range. More research is needed on Sound Check specifically.
On Quora, users recommend the Equalizer FX app for improving sound on iOS devices, though it likely only enhances the perceived experience[2]. By allowing manual adjustment of bass, midrange, and treble, users can tweak the sound to their preferences, which may lead to higher enjoyment.
Overall, while the objective audio quality may remain unchanged, the ability to customize the frequency response could improve a user’s subjective listening experience. More controlled tests are needed to confirm these apps’ impact on perceptual quality.
Considerations for Different Audio Setups
The impact of sound enhancer apps can vary greatly depending on the audio playback setup being used. Results on high-end over-ear headphones like the Sennheiser HD 600 will be very different compared to tiny smartphone speakers or earbuds.
In general, the benefits of sound enhancers are most apparent on lower quality speakers and headphones. The algorithms can help compensate for lack of bass or treble, masking noise, and distortion issues. However, many audiophiles argue this artificial processing makes music and audio worse on high-end reference headphones and speakers designed for accurate reproduction.
According to a thread on Audiogon’s forums, headphones have a more direct and intimate listening experience compared to speakers. People may perceive changes from sound enhancers more positively due to the proximity and isolated nature of headphones.
Overall, sound quality preferences are highly subjective. The impact of audio effects depends entirely on someone’s listening equipment and personal tastes. While apps may provide an improvement on some devices, the benefits are less noticeable for audiophile gear designed for uncolored accuracy.
Impact on Listening Experience
Sound enhancer apps can have a significant impact on the listening experience for users. According to research from The Benefits of Audio Enhancement Services, enhancing audio can create a more dynamic and high-quality listening experience. The study found that subtle boosts to clarity, spatial imaging, and frequency response resulted in greater enjoyment and reduced listening fatigue for users.
Other studies have looked at how sound enhancement impacts different demographics. A study published in the Journal of the Audio Engineering Society found that older listeners tended to prefer enhanced audio over original recordings, reporting it was easier to hear details and required less effort to listen to. Enhanced audio has also been shown to improve listening comprehension for non-native speakers and those with cognitive impairments.
However, there are some risks with over-processing audio. As this Apple user discussion points out, heavy handed enhancers can reduce mid-range clarity and add unnatural reverb. The key is striking the right balance between boosting audio quality and preserving the integrity of the original recording.
Risk of Artifacts and Distortions
One downside of using sound enhancer apps is the risk of introducing audio artifacts and distortions that degrade sound quality. The amplification and processing applied by these apps can cause clipping, where the signal gets flattened at maximum amplitude. This results in a distorted sound on loud passages (Source 1). Sound enhancement may also introduce background noise or hissing, as the noise floor gets amplified along with the audio signal (Source 3). Apps that boost only specific frequency ranges can make certain instruments or vocals overly pronounced, resulting in an unnatural, fatiguing quality.
These types of audio artifacts are more likely to occur when using sound enhancer apps with already loud or poorly mastered audio. The additional amplification pushes the signal past the point of clipping. Enhancement works best on audio that has quieter dynamics to begin with. Users should listen carefully for added noise, distortion, or emphasis on particular frequencies when evaluating these apps.
Alternatives for Audio Enhancement
While sound enhancer apps can boost certain audio aspects, there are other ways to improve your listening experience without relying on potentially unreliable software.
One alternative is to use a hardware equalizer or Digital Audio Converter (DAC). External DACs often allow finer control over the frequency response curve and can drive higher-impedance headphones properly. Models like the FiiO E10K TC offer both an equalizer and a headphone amplifier at an affordable price point.
Upgrading headphones or speakers can also significantly improve sound quality by offering better frequency range, distortion performance, and acoustic design. Consider moving to open-back headphones, planar magnetic drivers, or monitors/speakers matched to your room size.
If possible, listening to lossless audio formats like FLAC and ALAC preserves more detail compared to lossy compression like MP3 and AAC. Lossless files retain the full fidelity of the original recording. Hi-Res lossless streaming is now available through services like Apple Music.
Finally, consider repositioning speakers, adding acoustic treatment panels, or modifying room layouts and surfaces. Proper placement in an acoustically treated space often enhances the listening experience more than software alone.
Conclusion
The evidence suggests that sound enhancer apps can provide some benefits, but also have limitations. They can help improve perceived audio quality by amplifying quiet sounds and optimizing frequency response. However, they may introduce audio artifacts or distortions, particularly on tablet speakers which already have physical limitations
Based on the testing, sound enhancer apps do often measurably boost certain audio metrics like loudness and dynamics. But the improvements depend greatly on the speaker setup. Enhanced audio processing is unlikely to improve actual audio quality from phone or tablet speakers beyond what the hardware can reproduce.
For those looking to get more volume or clarity from their mobile device’s built-in speakers, sound enhancement apps may provide a perceptual boost. But expectations should be set accordingly, as tiny speakers can only do so much. Those wanting substantial audio improvements would be better served by investing in higher-quality headphones or external speakers.
In the end, while sound enhancer apps can squeeze out some gains, quality speakers or headphones remain essential for premium audio reproduction. The apps may benefit casual listening, but should not replace quality hardware upgrades for serious listeners
.