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86 points stargrave | 25 comments | | HN request time: 0.41s | source | bottom
1. cies ◴[] No.40084765[source]
This is REALLY important software nowadays imho.

I'm old enough to have spoken to people on analogue land lines: the sound was crisp, you could hear small background noises, you could hear someone breathe.

Nowadays we usually speak to people on digital lines that are highly compressed (to the extend that is messes with the sound quality), low freq range (no bass, very high sounds) and cut up (without enough sound or when then other party makes more sound the stream is completely interrupted).

And it does not have to be like this! All of this is in favour of the network operator (or centralized chat servers e.g. whatsapp) trying to save some data/money. While many of us have paid for unlimited data!

On top of that much of the conversations are not properly e2e encrypted!

I've used Mumble to speak to people I love over long distance and the quality is just so much better: it's like the analog experience of my childhood. Hearing ever breath, background noise and all in high quality makes all the difference some times.

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2. cies ◴[] No.40084877[source]
Cool project anyone reading this may be interested in:

https://github.com/Johni0702/mumble-web

I've never used it but it should make having a p2p conversation through Mumble as easy as pointing your browser to some URL. UX matters (Mumble clients, including mobile apps, are not very user friendly last time i checked: they require some level of skill to use them)

Unmaintained for the last 4 years, sadly.

3. thaumasiotes ◴[] No.40085105[source]
> I'm old enough to have spoken to people on analogue land lines: the sound was crisp

You're old enough to have forgotten what land lines sounded like.

They intentionally dropped frequencies from the audio signal so that they wouldn't have to carry the data contained at those frequencies. This is why nobody ever sounded like themselves over the phone.

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4. cies ◴[] No.40085748[source]
> They intentionally dropped frequencies from the audio signal so that they wouldn't have to carry the data contained at those frequencies. This is why nobody ever sounded like themselves over the phone.

I remember switching from early GSM phone to a landline because I like to hear my love breathe

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5. Sammi ◴[] No.40085778[source]
Old phone signals (Plain old telephone service or POTS) cut off frequencies above 4 khz. You cannot hear the difference between f and s, as these are higher frequency sounds at around 8 to 12 khz. You'd have to say f like in Fred or s like in Steve? Cause you literally could not hear the difference.

This is the reason broadband internet (ADSL) is called broadband. Because dial up internet used the POTS frequency band below 4 khz, and broadband used the (broad) frequencies above.

It's also the reason you'd have to get a technician out to your house in order to get ADSL. They would install a frequency cutoff filter on the phone line into your house, and hookup the landline to the below 4 khz side and the ADSL modem to the above 4 khz side, so the POTS signal would not interfere with the ADSL signal.

replies(1): >>40088284 #
6. thaumasiotes ◴[] No.40086265{3}[source]
Remember what you like. The facts are that sound over landlines was not crisp, and in fact was a train wreck.

It's particularly ridiculous that you're complaining about digital lines having a low frequency range.

Whatever you remember, it isn't reality.

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7. lhamil64 ◴[] No.40086597[source]
I wonder if it was more of an issue with the mic and/or mic placement on phones? Old landline phones had a large mic right by your mouth, whereas cell phones have little pinhole mics near the bottom of the phone.

I feel like I've actually noticed the opposite. My parents still have a landline, although it's basically VoIP (through their cable company) but it's connected to the analog lines in their house. I've noticed they generally sound clearer on their cell phones than they do on the landline.

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8. j45 ◴[] No.40086723{3}[source]
It’s different audio codecs and data connections which can be changed and adjusted.

Voice over mobile data will benefit from a different type of data compression relative to how data packets are handled in a cellular radio vs a wired internet.

The landline service could be as clear or clearer than mobile data, it just isn’t configured to do so in your case. I have seen VoIP setups using a high quality codec and a handset that can use those frequencies.

Phone companies use different setups that compress to their advantage for many more callers.

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9. slackwaredragon ◴[] No.40086748{4}[source]
I remember landlines fondly, it felt like I could hear people better back then. At the same time, I also remember the 4khz cutoff. It was the reason music sucked over landlines. Like if you were listening to music with a friend from highschool over the phone, it'd have no depth and you couldn't understand half of it from lyrics to beats. Hold music was a lot worse back then, these days it doesn't sound near as bad.

I think for a lot of us later Gen-X and older Millennials, as we age our ears don't work as well as they used to. Especially those of us like me that didn't heed good ear protection. I can't speak for everyone, but I suspect if today me tried to talk to someone on a landline back in the early 90s it'd still suck as bad as it feels like it does with cellphones today. We get more range with our phones now but our ears have a harder time processing it.

Just a thought.

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10. thfuran ◴[] No.40086775{3}[source]
Cell phone audio traditionally only covered 300Hz-3.4kHz before being lossily compressed down to 4kbps (or sometimes higher, depending on network, load in that service area, etc). That is complete shit. Recently, there have been other protocols adopted with greater bandwidth (all the way up to 7kHz, which is still several khz short of covering all the content of speech, but considerably less terrible) and less compression, but if you have audio that's actually good and not merely passable, it's probably because your phone is actually transmitting audio as voip, with a much better codec then is used for cellphone audio transmitted over the standard channel.
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11. lxgr ◴[] No.40087288[source]
How old of a landline are you talking about here?

Anything newer than (heavily depending on the country, probably) the 70s or 80s or so would have been very likely PCM u-law or a-law at 64 kbps (i.e. 4 kHz audio bandwidth at 8 bit), which is literally a mandatory codec in WebRTC.

It would have to be a really old, purely analog baseband line without filters (maybe a local call between offices), frequency modulation etc. to preserve more than the typical 4 kHz of audio bandwidth you'd get on these. Inter-trunk connections were often frequency multiplexed to fit more channels onto a physical wire, which also limited them to 4 kHz.

Today, 64 kbps gets you much farther using a modern codec like Opus. WhatsApp sounds better than any landline or native mobile phone connection I've ever used in my life.

> (or centralized chat servers e.g. whatsapp) trying to save some data/money

WhatsApp uses P2P for (non-group) calls if at all possible.

There's also a "save data for calls" option in the settings which is off by default.

Modern codecs are so good, adding even more data would literally not make any discernible difference. A sizable fraction of all data transmitted/received by modern VoIP is IP and UDP framing overhead.

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12. lxgr ◴[] No.40087406{3}[source]
GSM was indeed heavily compressed (voice channels were only around 12 kbit/s, compared to 56-64 kbit/s on landline), but comparing a modern VoIP codec like Opus (which is what almost every VoIP solution uses these days) to GSM FR or even EFR compression is like complaining about 64 kbps MP3 compressed by an early 2000s codec sounding bad and going back to vinyl for quality.
13. ◴[] No.40087442{5}[source]
14. lxgr ◴[] No.40087503{5}[source]
Very good point – the "landline generation's" ears have aged considerably since the 90s.

On top of that, I think many remember "landline quality" in terms of a relative comparison with potato-quality early mobile phone codecs, analog mobile phones, heavily compressed discounted long-distance calling circuits etc. of the time.

Yes, landlines were better than any of that, but it doesn't mean that they were actually good by today's standards.

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15. lxgr ◴[] No.40087531{4}[source]
Ironically, you've got a better chance of getting acceptable quality on mobile-to-mobile calls these days than when calling from a landline:

The big mobile carriers actually have VoIP interconnects preserving wideband audio, while connecting to an (especially smaller) landline carrier might still involve a circuit switched path (going to the physical location of the area code dialed, too!) that inevitably forces everything through a 4 kHz, 8 bit bottleneck.

16. aftbit ◴[] No.40087688[source]
Mobile connections are often especially crap, using something much lower bit rate than G.711 µlaw. Even modern landlines use voice activity detection and comfort noise generation instead of just passing through the background sounds.

I've never used WhatsApp to call. I have used decent SIP connections with G.722 Wideband or OPUS. They sound better than the old landlines. Discord sounds better too. Signal, much worse.

I think often the problem is that cell phones really have crappy speaker and microphone placement for calls, as basically nobody actually makes calls on them anymore.

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17. cies ◴[] No.40087916{4}[source]
Maybe i dont live near you.
18. cies ◴[] No.40087946{6}[source]
> by today's standards.

Which? Whatsapp call sound shit. Mobile phone calls sound shit.

I did Mumble to get some acceptable quality.

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19. lxgr ◴[] No.40087977{3}[source]
These days, unless you're on 2G or 3G (if they're even still available in your country), mobile phones will often use AMR-WB or EVS when calling over IMS (i.e. VoIP over LTE or 5G), which are both wideband and considerably better than G.711 (and probably even G.722; while they have lower bitrates, they're also considerably more modern).

The problem is that when calling across networks, the connection might still go over a legacy circuit-switched exchange, and that compresses everything down to narrowband again.

I hope that whoever regulates the PSTN in the US will force a switch to all-IP interconnects at some point, since now we get the worst of both worlds (often somewhat lower reliability due to badly managed VoIP services, combined with potato quality because of a legacy interconnect somewhere between VoIP networks).

All IP could also provide much more efficient routing: Right now, as I understand it, if you're calling somebody with a 212 area code and both you and the callee are physically in San Francisco, your connection might still be routed through some circuit-switched exchange in Manhattan, which isn't great for latency or high availability.

20. vel0city ◴[] No.40087988{4}[source]
G.711, the standard encoding for home phone systems since they went digital, is usually filtered at 300–3400Hz as well. Chances are if you had a home phone in the 80s or 90s it was filtered at 300-3400Hz somewhere along the path.
replies(1): >>40088714 #
21. lxgr ◴[] No.40088066{7}[source]
> Whatsapp call sound shit.

Not for me; it's way better than any landline I've ever used.

Not sure what we're doing differently – are you sure it's not your or the other party's speaker or microphone?

> Mobile phone calls sound shit.

Not for me either, at least not when EVS ("HD voice") is used, which is more often than not these days when calling friends/family.

2G connections used to sound quite bad, but since 4G, the limiting factor for me has been the other side being on a landline (mostly for business calls), which usually doesn't support wideband audio.

22. vel0city ◴[] No.40088085{7}[source]
WhatsApp uses opus for its voice functionality.

The default codec configuration for Mumble is opus.

23. lxgr ◴[] No.40088284{3}[source]
Pet peeve: This is why we use "broadband" as a synonym for "fast internet", but we should stop using it like that, since it completely neglects the symbol rate in that equation :)
24. lxgr ◴[] No.40088714{5}[source]
And the history of that filtering even predates digital lines, due to frequency multiplexing: https://en.wikipedia.org/wiki/L-carrier
25. lxgr ◴[] No.40090609{4}[source]
I'd not really call it different packet handling (except for some of the earlier, mostly 2G ones not providing FEC at lower layers and delegating some level of error concealing to the codec, as far as I remember):

The main difference is that the bandwidth available was just much lower, so mobile codecs are compressed more. (Satellite phones take this to the extreme – 2.4 kbps is a typical data rate after compression there!)

But so were e.g. international trunk lines; they squeezed a lot more than one voice channel into 64 kbps using compression, silence suppression etc.

> The landline service could be as clear or clearer than mobile data, it just isn’t configured to do so in your case.

An analog landline has relatively little chance of ever gaining wideband support, since that would require swapping out line cards at the provider, and the trend seems to be to get rid of these entirely (in favor of a VoIP adapter in the CPE).

I think I've once used "HD voice" on a "landline" when calling a mobile phone, but that only worked because my home router was actually doing SIP in the background.